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TwinMOS PC3200/DDR400


Date
: 03/8/03 – 12:14:03 AM

Author
:

Category
: Memory

Page 1 : Introduction

Manufacturer: TwinMOS
Price:

Introduction

Overclocking is the art of running a piece of hardware (in our case) at speeds higher than the stock rating in order to achieve a "free" performance boost. The current PC contains several parts that can be overclocked but the three most important parts are the CPU, the video card and the main memory (RAM). Overclocking one of these parts (or a combination of them) will result in the biggest performance increase one can expect.
Back in the days prior to the PII 300, which was the first CPU to have its multiplier hard-locked, people were overclocking their processors by changing the multiplier. As you may or may not know, overclocking a CPU can be done in two different ways: either you change the multiplier or you increase the front side bus. The CPU speed is achieved by multiplying the multiplier with the FSB. Below is an example …

Intel Pentium4 1.8A = 1800MHz = 18 x 100MHz (multiplier x front side bus)

There are two ways to overclock this CPU: turn the "18" into a "19" and get 1900MHz (19×100) or increase the FSB from "100MHz" to, for example, "110MHz" and get 1980MHz. Nowadays, both Intel and AMD are locking the multiplier of their CPU's to a certain value so you can not change it anymore (AMD processors can be unlocked by closing certain bridges on the CPU – Check out the O² Forum for more information). The conclusion of this decision means that people who want to overclock
must
increase the FSB (unless you unlock your AMD CPU). Is this a bad thing? It all depends … Increasing the FSB to overclock your chip will give you more "free" performance since instead of just increasing the CPU frequency, you are also running your other devices at a higher clock. In order to pull this off without BSOD's or other instabilities, you need two things: a good motherboard that comes with all the tweaks you need to change the FSB, increase voltages, set PCI-bus speeds, … and also high quality random access memory or RAM.

The main memory will be running at the same speed as the front side bus (unless your motherboard can run it at -33MHz, but that will NOT give you a performance boost … it is only a good idea for people who's memory can not take the boost) so it is very important that you select a brand that allows some "breathing" room (or do we call it overclocking potential). One of those brands is TwinMOS and today, OverclockersOnline.Com will be testing (read: torturing) their 256MB PC3200/DDR400 memory stick. At the present moment, the fastest non-overclocked DDR rating is PC2700/DDR333 which means the TwinMOS stick should be able to keep up pace for a while ;). Of course I am very interested to see if this memory module can live up to the dream, and whether or not it has any overclocking power in it.

Page 2 : Specifications

Specifications

Here's a copy/paste from the official TwinMOS website:

- Double Data Rate architecture
- MRS cycle with address key programs
- CAS latency: CL2, 2.5
- Burst length: 2, 4, 8
- Burst type: Sequential & Interleave
- 2 variations of refresh
- Auto refresh
- Self refresh
- Serial Presence Detect support
- 2 Banks to be operated simultaneously or independently
- Package: TSOP/CSP
- 184 edge connector pads
- Clock frequency: 133/166/200MHz
- SSTL-2 interface: 2.6 Voltage +/- 0.2V

The stick that was sent towards the O² test lab is a 256MB PC3200/DDR400 stick rated at CL2.5. PC3200 actually means that this memory can have a maximum throughput of 3.2GB/s when running at DDR400 speeds. DDR400 means the memory is rated at 200MHz and at that speed, TwinMOS is rating it CL2.5, which means it has a CAS Latency of 2.5. The CAS Latency has a pretty big impact on the performance of your memory, so you should always to run it at the lowest setting (most often, this is 2). If one had to choose between running his memory at 166MHz CAS2 or i.e. 180MHz CAS3, it would be a wise decision to run it at 166MHz/CAS2 as it will result in a bigger memory throughput and thus a bigger gain of system performance!

Our test stick is not fitted with heatspreaders, which is a feature other manufacturers tend to install on their fastest modules. When installed correctly (with paste and good contact between the chips and the heatspreader), these things could allow you to overclock it even more … but when installed badly, they will capture the heat instead of remove it … not good! TwinMOS rates their stick at 2.6V with a margin of +/- 0.2V. This means you could safely increase the voltage up to 2.8V without fearing about the life of your memory module. Some motherboards, especially EPoX ones, allow you to push your memory up to 3.2V. This is not a good idea if you don't have sufficient airflow over these sticks, because they will get very hot and will die a lot faster …

Although it is rated at 200MHz, it does not mean it won't work on older motherboards, which use a lower FSB. This stick is, like any other DDR memory stick, 100% back-compatible. Running it at 100MHz, 133MHz or even 166MHz will work just fine, and you'll be able to use even faster timings.

As a final note, I want to point out that "officially" there is no PC3200 standard (yet) since PC2700 is the fastest official speed rating currently available. This means that the PC3200 memory sticks out there are in fact hand-picked PC2700 parts, guaranteed to run at a 33MHz faster clock speed.

All the specs are clear, it's time to take a look at some real-time performance! Let the games begin …

Page 3 : Testing

Testing

First, a quick glimp at the test system:

- ABIT ABIT IT7 MAX2
- Intel Pentium4 1.6A CPU
- TwinMOS 256MB PC3200 DDR400 memory
- AOpen GeForce4 Ti4200 video card
- Western Digital 20GB 7200RPM IDE hard drive
- WindowsXP Pro + all the latest drivers

For this test, I decided on using a multiplier locked Pentium4 1.6A because of its low multiplier (16x) and secondly, its overclocking potential. Combine this CPU with the highly overclockable ABIT IT7 MAX2 which I reviewed a few weeks ago, and you got one killer setup, awaiting some sweet bus pumping!

At default speeds, the system booted just fine and all was well … In this case, default means 100MHz FSB which is only half the speed at which this memory is rated, so it would be pretty bad if things would go wrong already huh?

(note that the pic shows the memory on a Soyo board, although all tests were performed on the ABIT IT7 MAX2)

Immediately after, I had the system up and running @ 133MHz FSB, everything at default voltage. The CPU was now cruising along at 2.133GHz and everything was fine of course! Next stop … 166MHz FSB. Again, the system posted fine but hung when WindowsXP started its loading procedure. Nothing to be worried about here, after upping the CPU Core Voltage to 1.6V, everything was fine and rockstable at 2.66Ghz. Since I know my P4 1.6A maxes out at around 2.7GHz, I decided to increase run the memory asynchronous from the FSB from here on. Note that this will NOT give you much performance gain in games, applications, … but it does allow us to see how high the memory can actually go without the CPU limiting our achievements.

The IT7 MAX2 allows me to configure the DRAM Ration and once I set it to CPU:DRAM – 4:5, I had my memory running at (166MHz x 5)/4 =
207.5MHz
. Note that the TwinMOS stick is still running at CAS2 speeds, while it is rated at 2.5 @ 200MHz! After running a few loops of 3D Mark 2001SE and running SiSoft Sandra 2003 a few times, I knew this was going to hold. Time for more!

I increased the FSB to 170MHz, which results in a memory speed of (170MHz x 5)/4 =
212.5MHz
. Again, the system posted fine but when WindowsXP was loading, it suddenly rebooted itself … Since I already had this CPU running stable with a FSB of 175MHz on the same motherboard, I knew the RAM was causing this. I switched the CAS from 2 to 2.5 and kept all other settings untouched. Bingo! WindowsXP loaded just fine and all was well. Note that you are better of at 207MHz CAS2 than at 212MHz CAS2.5 for the reasons I explained previously. When I tried higher speeds wouldn't make it in the O/S, whatever I tried …

Now let's take a look at some benchmarks to see what these results translate to …

Page 4 : Benchmarking

Benchmarking

3D Mark 2001SE

SiSoft Sandra Memory Benchmark

Page 5 : Conclusion

Conclusion

TwinMOS has surely done a terrific job with their fastest memory sticks! These DDR PC3200 memory modules perform just like TwinMOS says and more! Instead of running at the rated CAS2.5 setting, I was able to run at CAS2 all the way up to 207MHz! When switching to CAS2.5, the memory was good for 212MHz. I don't think anyone out there will there to complain with these achievements, and once you check out the price tag on this 256MB stick, you will agree with me that this memory stick deserves the one and only official
Overclockers Online POWER Award
! Thanks to TwinMOS for giving us the opportunity to review this killer stick!

Good

- CAS2 @ 207MHz!
- CAS2.5 @ 212MHz
- Price

Bad

- Nada, nothing :)