DDR Ram Guide
DDR memory is getting popular now.
However, it is rather hard to know the overclocking limits before buying. Thus
we came up with this DDR ram guide. This guide is designed to test the limits of
DDR modules on the market and we will update it as time changes.
Before we being, let's have a look at the terminologies.
The DDR convention is used to mention the speed of the ram is running. The PC
convention is used to denote the bandwidth the ram provides. Okay, enough is
enough; let's have a look at the candidates.
PC-2100 (DDR-266) Group
Corsair ValueSelect PC-2100 Cas 2.5
(Super Man Ram??)
Corsair realises that not everyone are willing to pay the premium for the XMS
range thus they also have the ValueSelect range. The ValueSelect range is, from
Corsair, "Low Cost Memory Solution for price-sensitive applications." I never
like the idea of "value" range from my previous encounters with other firms, as
they often perform poorly and come with not-so-cheap price. However, the
ValueSelect ram is one of the cheapest PC-2100 ram on the NZ market, 15~20%
lower than the average ones. This grabs my attention as it is really cheap. We
will see how it performs in the benchmark section.
The chip used is rated at 7.5ns which translates to 133 MHz (or 266 MHz)
theoretical operation. I can not identify the maker of the chip, an S in the
middle. Maybe Superman is the brand?
Update: Various readers have commented that the ram is made by
SpecTek who is a part of the Micron Technology family.
Crucial PC-2100 ECC Registered
We can see this stick uses Micron chips. Now, Crucial with Micron chips had
always been a HOT commodity in overclocking society. They've been rumoured to
hit 180 MHz mark despite being a PC-2100 module.
Please note: You CAN NOT mix registered ram with normal unbuffered rams. It is
also adviced that you use registered ram if you are planning to have more than 3
sticks in the system to ensure maximum system stability.
Kingston ValueRAM PC-2100 CL2.5
Kingston is a well-know name in memory industry. They produce some of the
highest quality products on the market. The ram chips used in this module is
made by Nanya, rated CL=2.5 at 133MHz. I really look forward to test this module
since my old Kingston SD-RAM had a good overclocking potential.
PC-2100 (DDR-266) Group
TwinMos PC-2100 CL2.5
The recent surge in DDR price had deterred many from moving to DDR platform or
getting high-speed DDR-333 ram modules. Instead, many are looking at low price
ram modules and hoping to hit high FSB marks. TwinMos PC-2100 is exactly the
sort of ram people are looking for. This ram is said to have a good overclocking
potential with relatively low price. However, I "had" concerns with its
potentials after seeing its ram chips, elixir, a company I have never heard of.
We will see how it performs in the later section.
PC-2400 (DDR-300) Group
Tiny BGA is used for this DDR-300 module. The ram is rated at 6ns which
translates to 166.67Mhz operation. However, this is theoretical rating only; the
actual operational frequency may vary under different conditions. Interestingly,
the ram is rated at CL-3 however, DDR only have two ratings 2 or 2.5. Go figure.
PC-2700 (DDR-333) Group
Corsair XMS PC-3000 CL2 V1.1
Corsair XMS range has always been praised as the HIGHEST quality ram available
on the market, same goes to price. The improvements over V1.0 are the addition
of heat spreader and utilisation of higher density chips. The heat spreader is
more of a cosmetic addition rather than a function one, unless you are driving
this stick with 3V+ voltage. Corsair used some sort of thermal glue/conductive
tape to attach the spreader. I could not get it off the ram with a reasonable
amount of force thus there is no picture of the ram chip. The ram chip has a
density of 256Mbit therefore only 8 chips is need for 256MByte capacity. This is
great news for I845D users, who are short on memory banks, as it is classified
as single bank ram instead of dual banks, unlike most 256MByte module.
Note: Corsair guarantees that this module can run at 166 MHz with 2-2-2
setting and 185 MHz with 2.5-3-3 setting.
Back in Feb 2002, our Crucial PC-2100 ECC Registered lived up to its fame and
achieved an astonishing 187 MHz operation (2.5-3-3). Today, we are going to see
if Crucial can continue the tradition.
The memory chip used is still made by Micron technology. However, it is rated at
6ns instead of 7.5 for PC-2100 modules. This module is rated at CL-2.5 when
running at 333 MHz.
PC-2700 (DDR-333) Group
Kingmax is one of the first manufacturers to introduce DDR-333 modules, along
with TwinMOS. Let's take a look at some pictures first.
We were unable to obtain more information on the ram, as
ctSPD's Memory Readout Utility does not work with DDR ram. We can see the
ram is rated at CL 2.5 under 166/333Mhz operation. The chip used in this ram is
rated at 5ns which translates to 200Mhz operation. We will see if that is
possible in the benchmark section. The layout on the DDR-333 is a bit different
from the previous generation; maybe this is done to improve the electrical
signal under high operating speed.
TwinMos PC-2700 CL2.5 Version
TwinMos is one of the first companies to release a PC-2700 ram. However, there
are two types of PC-2700 release by TwinMos. The first one, the fastest one, is
the CL2.0 version using Nanya chips. The one we got is the lower rated one,
Hynix chips. We will see if we could get the one with Nanya chip. Hynix is
the former Hyundai, they merged with LGS earlier in the year. A quick visit to
Hynix revealed it is only rated at 133 MHz, Cas 2. TwinMos might have hand
picked the chips that can operate at 166/333 Mhz.
Samsung TCB3 PC-2700 memory chip had attracted quite a bit of attention in the
past month or so. This is due to their high overclockability and low prices. It
is perhaps one of the lowest priced PC-2700 modules on the market. The stick
we've got is built on Samsung PCB which is said to have the highest overclocking
potential. This PCB's layout is designed for single side operation as the back
of the PCB has no "traces". In my experience, single side ram modules always
offer better overclocking than the double-sided counterpart.
Note: It's been reported by our reader that the earlier batch of the CTL-CB3
offers a better overclocking potential than the current batch, DTL-CB3.
Unfortunately, we can not obtained a sample for test at the moment, as they were
sold out long ago. Here are some links to provide the experiences that people
PC-3200 (DDR-400) Group
Back in the early days of PC-2700, we had Samsung CTL-CB3, which was an
incredible overclocker. It was used on practically all of the high-end modules.
In the PC-3200 age, the WinBond BH-5 chip seems to be the next CTL-CB3. (Corsair
are using this chip, hand picked, for their XMS-3200 module)
From the pictures above, we can see that A-Data also uses the WinBond BH-5 chips
on their PC-3200 range. From the
datasheet, the HB-5 is rated at DDR-400 with a voltage of 2.6V. This is a
good sign, as some DDR-400 modules require 2.8V to operate. We shell see how it
performs in the following tests.
With the release of KT-400 chipset, DDR-400 modules will be the hot pick of the
month. Thus Corsair has release a new wave of XMS modules. From their
PDF, the newly released XMS-3200 is in line with JEDEC's DDR-333 speed.
(Overclockers do not give a toss about it.) Corsair advertised that the XMS-3200
is guaranteed to run at 400 MHz with 2-3-3 1T setting. We will find out if the
claim is true or not in the following benchmark section.
Unlike the XMS-3000 which uses Samsung TCB3 6ns chips, XMS-3200 uses Winbond
W942508BH 6ns ones. To be honest, I am a bit sceptical at this point since my
old OEM Winbond PC-133 did not make it past 140 MHz. However, knowing Corsair, I
am sure that the XMS-3200 will perform up to its advertised speed.
PC-3200 (DDR-400) Group
As with the DDR-333 case, Kingmax is the first company to release the DDR-400
memory modules. We can see from the sticker that this module is rated at CL 2.5
at 400MHz operation. The ram chip used is rated at -5ns which translates to
200MHz theoretical operation.
The DDR-333 and DDR-400 modules have similar layout. This makes us wonder if
Kingmax "hand-picked" the best performing modules and mark them as DDR-400.
It is worth noting that the PC refuses to POST at 200MHz while I left the DDR
voltage at 2.55V (default). However, the machine POSTed and got into Win2K when
the DDR voltage is raised to 2.85V.
Abit KR7-R Motherboard
AMD XP-1600+ CPU
Maxtor DM60 plus 30GB ATA100 Hard Drive
Leadtek WinFast GeForce2 Ti 64MB Video Card
Above is the BIOS screen shot for the RAM
setting used for testing. All the settings remained constant through out the
test, only Cas Latency, Trp, and Trcd were changed to test the ram under
As the DDR-333 and DDR-400 modules appear on the market, our Abit KR-7A
motherboard seems to be a bit dated due to lack of PCI dividers (max at 1/4). We
will be looking at upgrading the test bed in the future to accommodate high FSB.
For all the tests, DDR voltage was set at 2.85V instead of default 2.5V. This is
done to find the maximum overclocking potential of the ram. As long as one keeps
voltage under 2.9V, the ram module should be safe.
For the Kingmax modules, we tested under 2.5/2.85V and found out they performs
BETTER under high voltage, i.e. 2.85V. This is very interesting to see as
www.overclockers.com found Kingmax modules have a better performance
with default voltage.
Definition of stability: The machine will boot into Windows (obviously), finish
1 run of Sandra 2001 memory benchmark, 1 runs of 3D Mark 2000, 1 runs of 3D Mark
2001, and 1 run of Super Pi 1M calculation.
The following table shows the maximum FSB with respect to each setting for each
||Max overclocking % from
|TwinMOS PC 2100
|Kingston PC 2100
||Corsair XMS PC-3000
|More is coming
DDR -266 (Crucial DDR-266 is our top pick)
The Crucial lived up to its name. Despite being a PC-2100 module, it offers
overclocking potential that rivals PC-2700 modules.
The Kingston has a rather disappointing result, 138MHz at 2-2-2 setting. This
ram is not for overclockers.
The TwinMos lived up to its name, offering a 24.8% overclocking potential. This
ram would be the ideal choice for people on a budget.
Wow, the ValueSelect ram performs flawlessly at 162 MHz with 2-2-2 setting. This
is the best overclocking ram I've seen at this price range. For the price
sensitive people, you can not go wrong with this stick, 162 MHz with 2-2-2 and
170 MHz with 2.5-3-3. I challenge anyone who can come up with a better choice at
The Kingmax DDR-300 has similar max FSB regardless of the memory timing.
Generally speaking, reducing the memory timing would give around 5~10 Mhz more.
Maybe we have reached the limit for that module.
The Kingmax DDR-333 certainly offers a good potential for those high FSB
seekers. It can do 175 at 2-2-2. I don't know about you but to me it's damn
impressive. It provides a very healthy memory bandwidth to your system as well.
The TwinMos module performs badly in the 2-2-2 setting, sporting 150 MHz.
Anything higher than that would result in lock up in POST. However, the ram
performed flawlessly in 2.5-3-3 mode, sporting an astonishing 190 MHz, the
highest FSB yet.
Corsair XMS-3000 achieving an astonishing 180MHz at 2-2-2 setting and a new
height of 195MHz at 2.5-3-3. Overclockers, this is THE ram to get. You can't
go wrong with this module.
It is a bit disappointing to see that Crucial PC-2700 is only slightly better
than the old PC-2100 Registered counterpart. I was hoping that this module could
break the magical 200 MHz barriers. With the above said, Crucial PC-2700 is
still a good ram module, offering good overclocking potential. It is only
overshadowed by the Corsair XMS-3000.
Samsung PC-2700 is able to achieve a high operational frequency of 191 MHz at
2.5-3-3 setting. Its performance is just shy of our current king, Corsair
XMS-3000. It should not be surprising as they both used the same chip, Samsung
TCB3. However, Corsair handpicked the top batches. Overclockers on a budget
should consider it as a good substitute for the XMS-3000.
A-Data performed admirably, 195 MHz at 2-2-2 timing. I believe that this is the
first time a "budget" module can reach such a MHz. Again, I did not test any FSB
greater than 200 MHz due to the limitation of Abit's KR7A. This module would be
a perfect substitute to Corsair XMS-3200 for the overclockers who are on a
Well, the Kingmax DDR-400 module failed to impress me with 2-2-2 setting. It is
even worse than the Corsair PC-3000 module. However, it truly shines in high
FSB, reaching an astonishing 200MHz on our KR7A. At that speed, it may well be
that our board is holding back the ram. We will be doing a retest in the future
when official DDR-400 chipset hit the market. For the time being, this module
offers the highest FSB, 200MHz, we ever achieved on this test bed.
Ladies and gentlemen, we have a new winner here!!! The Corsair XMS-3200 is
capable of handling 2-2-2 setting at 200 MHz. This is a big leap from the
previous 180 MHz mark. I was unable to test FSB > 200 MHz, as our testing rig,
Abit KR7A, will not work properly after 200 MHz. (PCI bus at 50 MHz) We have no
hesitation in recommending XMS-3200 to anyone seeking THE best memory on the
Corsair XMS-3200 DDR400 RAM
PC-3200 DDR400 RAM
FPS vs increase in FSB
Some users maybe wondering, what is the
real-world benefit from high FSB and low Cas rating? I did a few benchmarks and
hope they would be able to answer the questions.
- Abit KR7 Motherboard
- AMD XP-1600+ CPU (Always fixed ~1400Mhz +/- 5MHz in the test)
- Kingmax DDR-333 256MB*2
- Maxtor DM60 plus 30GB ATA100 Hard Drive
- Leadtek WinFast GeForce2 Ti 64MB Video Card
I ran Q3D - Demo001 under different ram settings and game resolutions.
This is the low video bandwidth mode where graphics card should not be a
At Cas 2-2-2:
There is an increase of 18.57% in FPS when moving from 133 to 175MHz.
At Cas 2.5-3-3:
There is an increase of 14.77% in FPS when moving from 133 to 175MHz.
You need an extra of 10MHz to make up for lower Cas rating, i.e. FSB of 175 Cas
2.5-3-3 is on par with 165 Cas 2-2-2.
This mode is used to simulate what could happen when video card becomes a
At Cas 2-2-2:
There is an increase of 6.1% in FPS when moving from 133 to 175MHz.
At Cas 2.5-3-3:
There is an increase of 5.99% in FPS when moving from 133 to 175MHz. The
increase is less dramatic compared with 640*480*16*Normal mode. The GFX now
becomes the bottleneck since Q3 can only run as fast as the GFX can. Like we
said in various reviews, in gaming situation, your system will be as fast as
your slowest component, usually the GFX card.
Just out of interest, I repeated the test under 1024*768*32*Quality mode and
found virtually no increase in performance.
That's it for now folks. Check back sometime later for results on other modules.
With today's technology changing so quickly it is very
easy to get behind. But when you hear about the fastest memory or CPU you think
to yourself, "I have got to have it." Well, in truth, when looking at purchasing
DDR based memory, there are a lot of things that you have to take into
consideration. I am writing this article due to the fact that I frequently
browse hardware forums and sites and one of the more notable questions that
comes up all the time is, "What is the fastest memory?" or "What kind of memory
should I buy?" People typically reply back and say what the faster modules are,
or their opinion of different types of memory. What a lot fail to say are the
other interesting points that one needs to know in order to maximize his / her
system's performance, and at the same time spend money wisely.
DDR memory is available in a wide variety of different
speeds at the moment. Here is a short list of some of the more common types:
- PC1600 - DDR200 MHz (100x2)
- PC2100 - DDR266 MHz (133x2)
- PC2700 - DDR333 MHz (166x2)
- PC3000 - DDR366 MHz (183x2)
- PC3200 - DDR400 MHz (200x2)
- PC3500 - DDR433 MHz (216x2)
Many manufacturers produce these modules, Corsair,
Kingston, Samsung, Mushkin, Geil, XtremeDDR, and Crucial just to name a few.
Each of these companies produces memory that is "rated" at a certain speed. They
stand by their product and claim that the memory will run as fast as its rated
speed. As I stated before there are many other factors though. For instance, if
you are using a DDR333 motherboard, then your motherboard definitely supports
DDR333 or PC2700. Anything higher than PC2700 you will have to overclock to get
it to run at that speed. To put it simply, just because you buy PC3500 doesn't
mean that you will be running 433 MHz (DDR). You have to overclock to that speed
because the current standard only supports up to PC2700. To overclock your
memory you must raise the front side bus which will typically overclock your
AGP/PCI slots, CPU, and DIMM slots. Anytime you overclock, you run the risk of
damaging parts or you might have issues with stability and performance of the
rest of your system. Selection of memory will be directly influenced by the
components in the rest of your system.
The main component that you need to take into
consideration is the motherboard. It will have to be able to handle the speeds
that you want from your memory. So the first thing to think about when
purchasing DDR memory is, "Will my motherboard be able to handle the speeds that
I want to run at, and does it provide options in the BIOS that I will need to
overclock my memory?" I would suggest reading up on your motherboard and finding
out the results that others have had. This is key and will greatly aid in
deciding which memory you should purchase.
For AMD Systems:
Let's start with the AMD platform. When picking DDR memory
for an AMD based system you need to be really picky about what you buy. There
are very few AMD based motherboards at the moment that can run at DDR400 speeds.
Most support 333 MHz but some are just better overclockers than others. The good
thing about the AMD platform is that you can unlock the multiplier on the chip.
The multiplier x FSB (front side bus) gives you your CPU speed. For instance 133
FSB with a chip that has a 10 multiplier would give you 1,330 MHz (133x10) or
1.33 GHz. Since you are raising the FSB to overclock your memory, your CPU will
come into play. It will be getting overclocked and at some point it will not be
able to overclock any higher. This could stop you from maximizing you RAM. So by
unlocking the CPU and lowering the multiplier, you could run the processor at a
speed you know it can handle but overclock the FSB even higher to maximize the
memory bandwidth. So let's say you don't want to overclock your CPU but you want
to get your memory to run at its maximum, which just happens to be 400 MHz
(200FSBx2). Using the same CPU as the one in the first example and considering
you have a good motherboard, you could use the 6.5 multiplier and run your CPU
at 1.3 GHz (200x6.5). Issues that this high of a FSB are mainly PCI/AGP clocks
as they are now running out of specification which cause instabilities, video
distortions, or glitches (AGP tearing), hard drive issues, and the list just
goes on. Luckily most 333 motherboards provide a 1/5 divider which allows you to
put your AGP/PCI closer to spec. At 133 FSB on a 333 motherboard your AGP/PCI
clocks run at 66/33. This is uses a ¼ divider for the PCI. At 166 FSB you could
use the 1/5 divider to bring your AGP/PCI back to spec, but anything higher will
make you run out of spec again. So when trying to run at speeds over PC2700 you
might run into issues with your AGP/PCI clocks. In short your video card, hard
drives, soundcard, etc. will determine how high you can go as well the memory.
As you can see when running an AMD machine and trying to
maximize memory, there are a lot of other issues that that you have to deal
with. Major concerns are the AGP/PCI clocks and the CPU speed. Also to really
maximize the RAM it's nice to have voltage options up to 3.2 volts on the VDIMM
such as the Epox 8K3A. I like AMD machines myself but they just cannot seem to
overclock the memory like the Intel Platforms do.
For Intel Systems:
Picking RAM for an Intel machine is not any easier than
picking it for an AMD rig but you can overclock easier in some aspects and
harder in other when compared to AMD. Unlike the AMD, Pentium 4 multipliers
cannot be unlocked. So you can only overclock the RAM by upping the front side
bus and the rest of the system. The good thing is that on an Intel platform you
can lock the AGP/PCI clocks in at 66/33, this is a very nice feature that I
like. You don't ever have to worry about if your video card, sound card, hard
drive, etc. is giving out. Other things like we discussed earlier like voltage
options, etc still will play a part in deciding process.
Okay since we cannot unlock the multiplier what can we do
to make the ram run faster? Well luckily Northwood P4's are very good
overclockers to begin with. They are able to achieve high FSBs on good
air-cooling. Also there are options on the Intel platform motherboards such as
RAM ratios. For instance, I have an Abit IT7, let's say I can overclock my CPU
to roughly 160 FSB with good air-cooling using a P4 1.6A. This would mean the
chip is at about 2.56 GHz and the RAM is set at 1:1 (FSB:RAM) so I would be
running it like the AMD rig. It would be 160x2 so it would be 320 MHz DDR but my
IT7 has a 3:4 memory ratio. So at 160 FSB the memory would be at 213x2 which
would be 426 MHz! This is great for people who want to use PC3500 and run some
really great memory speeds. Now you run into issues again though. Let's say you
have really good cooling for instance. Something that lets you overclock to say
190 FSB. If you were to use a 3:4 memory ratio the memory would be at 506 MHz
(253x2). Let's also say that you have some PC3500 that you want to use, well
there are not many sticks of RAM that can run at 506 MHz. But if you were to use
the 1:1 memory ratio then you memory would be doing 380 MHz. You would be
underclocking you memory below its rated specifications. So what do you do? Well
you could get a new chip with a bigger multiplier that will overclock to 160's
FSB with serious cooling such as a 2.8 with its 21 multiplier. Or you could run
your CPU lower than what you max out at so that you can use the 3:4 divider.
This is the exact spot I am in at the moment. In my situation I can run my CPU
at 193FSB but I have to use the 1:1 ratio. I don't want to go back to a lower
FSB because I like my CPU to be maxed out. So what am I going to do? I am going
to get a chip with the larger multiplier so I can have super fast CPU speed as
well as memory speed.
So you see there is a lot to Intel platforms as well as
AMD. You have some good benefits and some bad for each. You have to choose your
RAM wisely considering what kind of chip you have and what FSB you can run. I've
seen some people get in a situation where their CPU was a bad overclocker so
they could not max out the RAM, so they got extreme cooling and were able to
overclock the CPU a lot more but got stuck in the situation that I am in.
When purchasing memory you have to find the perfect
balance of everything if you want your components to be running at their full
potential. This is called the sweet spot. Both AMD and Intel machines have a
sweet spot where you have the perfect balance of memory bandwidth as well as CPU
Now that we have covered the AMD and Intel platforms
separately by what each machine has to offer and how it affects your choice, now
let's talk about the last thing that applies to both. Memory timings are just as
important as overall speed. Some people buy PC3500 and expect it to run at 3500
speeds and forget that not only is there a rated speed, but every stick of RAM
has its own memory timings. For instance, some are CAS 2.5 3-6-3 2T and some are
CAS 2 3-6-3 1T. These timings will influence how well you can overclock the
memory as well. Since this is not a overclocking guide I will not go into what
the timings mean but I just want the buyer to keep in mind that his memory is
rated to run at a specific speed at specific memory timings, anything faster and
you are overclocking your memory just like any other component, which mileage
With DDR memory now in the affordable price range, and motherboard manufacturers
phasing out SDRAM on nearly every new board, it looks like DDR is definitely
here to stay. Even corporate giant Intel dumped the once-all-mighty RAMBUS, and
opted for integration of DDR support into their chipsets and motherboards, only
to join forces and rise to power with the P4. Memory manufacturers are doing a
good job of producing high-quality RAM for demanding systems and the
ever-changing industry, but how do you know what's what on the memory front?
There are so many different DDR modules available these days, it's hard to know
which one will offer the best performance.
Tweakers Australia has come
up with an article that will address several of these queries, including the
different brands and models on the market, how they perform, and how they
compare to each other. We'll be starting off with 4 DDR333 sticks and 1 DDR266
stick, and adding more as we get a hold of them. The DDR Memory Performance
Roundup will also feature regular updates and new testing procedures when they
are available… but for now we'll be checking out the bandwidth and timing of the
5 models we have here today, so lets get started!
DDR memory is the latest in
high-performance memory module technological advances. It offers twice the data
bandwidth of conventional PC100 or PC133 SDRAM, and is particularly well suited
for high-performance servers and workstations, which need optimal CPU-memory
performance. Double Data Rate (DDR) SDRAM (AKA SDRAMII) is precisely what the
name implies. A clock cycle can be represented as a square wave, with the rising
edge defined as the transition from "0" to "1", and the falling edge as "1" to
"0". In SDRAM, only one of these wave edges is used, but DDR SDRAM references
both, effectively doubling the rate of data transmission. Unlike 168-pin SDRAM,
DDR SDRAM utilizes a 184-pin plug. Although the basic motherboard technology
does not need to be changed, DDR SDRAM is not backward compatible on
motherboards designed for SDRAM.
Not many systems out there run a system bus of 166MHz, so without an overclocked
system your not going to benefit from the extra bandwidth DDR333 memory provides,
since both AMD and Intel currently make CPUs that only run on a 133MHz bus. A
lot of motherboards have a setting in the BIOS which allow you to set a divider
that adjusts the DIMM frequency, enabling you to run DDR333 memory in on a
system bus of 166MHz, 133MHz and even 100MHz. In my experience, running DDR333
in asynchronous mode doesn't do much at all, as DDR memory can only derive its
true speed and bandwidth from doubling the actual system bus in synchronous
For testing I choose ABIT's latest KT333 motherboard - the
KX7-333R - for it's
stability, and the extensive range CPU and memory settings in the BIOS. I
performed four tests on each stick including a 133/133 synchronous bandwidth
test, a 133/133 synchronous bandwidth test with more aggressive timings, a
133/166 asynchronous bandwidth test, and a 166/166 synchronous bandwidth test
using an overclocked AMD XP1600.
The ABIT KX7-333R officially
supports DDR333, along with the necessary PCI and AGP dividers. This meant that
running the system bus at 166MHz wasn't going to induce any stability issues
with the PCI and AGP buses, but running it any higher could potentially cause
problems. This is why we will follow up this article at another date with a
high-FSB comparison of the modules, using an unlock AMD CPU.
||- AMD XP1600+ (1.4GHz)
||- ABIT KX7-333R (KT333)
||- Apacer PC2100 256MB DIMM
- Apacer PC2700 256MB DIMM
- Kingmax TinyBGA PC2700 256MB DIMM
- Crucial PC2700 256MB DIMM
- OCZ PC2700 256MB DIMM
||- Maxtor 20GB 7200rpm ATA133
GeForce4 Ti4600 128MB
||- Enermax EG365-VE(FMA) Dual
||- Windows XP Professional
- SiSoft Sandra 2002
Established in 1997,
Apacer is a young and rapidly growing company within memory industry. With a
global reach of more than 1000 distributors worldwide, Apacer Technology Inc.
stands firm as one of the industries market leaders. According to Dataquest in
1999, Apacer is amongst the top five third party memory module companies
The Apacer PC2100 module features
16x NANYA memory chips, each rated at 6ns. The DIMM is double sided, and the CAS
Latency of the DIMM is rated at 2.5.
Apacer was one of
the first RAM manufacturers and offer PC2700 DDR333 memory for the consumer
market. The Apacer 256MB DDR333 module is rated at CL2.5, and features Samsung
memory chips rated at 5ns. The module is designed with memory chips on one side
Founded in 1989,
Kingmax Technology Inc. is a leading manufacturer of PC peripheral products in
Asia. Manufactured with high quality components to strict engineering and
quality standards, Kingmax manufactures and designs virtually every kind of PC
Card, memory upgrades and networking devices. Kingmax Semiconductor Inc. is the
first in the world to introduce the patented TinyBGA package technology which
drastically reduces the size of the chip itself and increases the overall
electrical and thermal performance of the DRAMs.
The Kingmax DDR333 PC2700 256MB
184-pin unbuffered DIMM is packaged with TinyBGA technology, and uses a DRAM die
geometry process of .15um. The advanced TinyBGA package technology drastically
reduces the size of the chip itself and increases the overall electrical and
thermal performance of the SDRAM component. Kingmax was also the first
manufacturer to release DDR333 memory.
Crucial was one of
the last manufacturers to offer PC2700 to the consumer, but the reason behind
this was so they could be approved by JDEC for the DDR333 standard. Crucial
Technology is a division of Micron Semiconductor Products Inc, a wholly owned
subsidiary of Micron Technology Inc. Located in Boise, Idaho, Micron
manufactures dynamic random access memory (DRAM) chips and assembles them into
memory modules for the global computer industry. Currently, Micron is the only
DRAM manufacturer in the US and one of the three largest in the world. Micron is
one of the top suppliers of memory to the major original equipment manufacturers
(OEMs) including Compaq, Gateway, micronpc.com, HP, and IBM. Crucial conducts
94% of their sales over the Internet, and is the consumer orientated sister
company of Micron.
The Crucial PC2700 256MB modules
features 16 Micron memory chips, each rated at 6ns. By cutting out the middle
man by choosing to do business over the Internet, Crucial also offers some of
the most cost-effective modules on the market.
OCZ Technology has
been criticized in the past for 'faking' faster memory just to get their modules
out onto the market before anyone else does. Other sources say that they provide
select hardware review sites with faster-than-actual sticks, for the purpose of
achieving higher scores in benchmarks. I have no personal ill-feeling towards
OCZ in any way, and up to date they have been consistent with producing high
quality memory modules incorporating some of the best chips from Micron and
Samsung. The module we received comes with a copper heatspreader on either side,
which made it very difficult to take snaps of the memory chips themselves.
The following graphs show a comparison of the
bandwidth figures from each module under each mode. Instead of showing you how
high we could clock the memory, I thought it would be interesting to show the
bandwidth comparison of the tested modules.
Overall the best
three modules were the Crucial PC2700, the Apacer PC2100 and the Kingmax PC2700.
I was disappointed with the performance of the Apacer PC2700, but was surprised
with the Apacer PC2100. The Apacer PC2100 delivers excellent performance and ran
without any problems whatsoever at 166MHz. As for the OCZ memory, apart from
having the best aesthetic qualities it came in second last.
Timing basically refers to the CAS Latency, Precharge to Active (Trp), and
Active to CMD (Trcd) settings usually found in the Advanced Options menu within
the BIOS. There is much hype about the effects of timing and how it can
dramatically increase performance, and the graph below gives a good
representation to the impact timing can have. The default timing for all modules
was 2.5-3-6-3 with 1T Command Rate and 4-way Bank Interleave, whist the more
aggressive settings for the comparison were 2-2-5-2 with 1T Command Rate and
4-way Bank Interleave. Here is a couple shots of the BIOS, with the two
different timing setups.
There wasn't one
module that had any issues with the more aggressive memory timings, and the
extra bandwidth offered from the tweaking is worthwhile. Once again, it looks as
if the Crucial PC2700, the Apacer PC2100 and the Kingmax PC2700 enjoyed the
timing the most out of the five sticks tested.
In summary, I have to give the performance award to Crucial. They have produced
an excellent PC2700 stick, and are one of the few companies that waited until
JDEC approved the DDR333 standard. The best value award is going to Apacer for
their PC2100 product, which has some great overclocking potential and performs
pretty much on par with the Kingmax module at 166MHz. As for looks, the OCZ
PC2700 scoops up this one as the only company that includes those cool copper
heatspreaders - despite having no effect on performance.