Overclocking

A RAM Stress Test Professional (R.S.T.) Pro2 card will be used to test for reliability as well as stability during our overclocking tests. The card is quite expensive, but if you're testing a lot of ram, or you're a technician troubleshooting systems, this card is well worth the money.

We proceeded with overclocking, and tested the ram via the memory tests on the R.S.T. Pro2 until we got a failure. In order to maximize our OC potential, we used a Pentium 4 3.6 ES, whose multiplier can be adjusted from 14-18 will allow a bit of FSB headroom on our MSI 915P motherboard. The board allows memory to run up to DDR2-710, which equals 1066FSB, so it should give us some headroom in overclocking. The power supply used is Cooler Master's RealPower 450W.

Timings	Max DDR2 OC	Pass R.S.T. Pro2
2-2-2-6	400	Yes
3-2-2-8	533	Yes
3-2-2-8	600	No
3-3-3-10	667	Yes
4-4-4-12	684	Yes

*Denotes running the ram synchronous with the CPU bus speed.

While we did not include every overclocking test/result in our results above, we did include some that were worth noting. The ram had no problems reaching its rated speeds and timings, and at 3-2-2-8, the system reached DDR2-600, but did not pass the R.S.T. Pro2 test. We were able to boot into Windows, but the system would flake out after multiple benchmark tests. At DDR2-684, the ram pass the tests with memory timings relaxed to 4-4-4-12.

Keeping things 1:1 (synchronous), we were able to reach 250FSB (DDR2-500) while keeping the timings at 3-2-2-8. This is the maximum CPU overclock we've been able to pull off from this board, so we've reached the board's limit well before the ram.

Test Setup

MSI 915P Platinum: Intel P4 3.6, 2 x 512MB Mushkin PC2-4200 CL 3, ATI X850 PE, 120GB Seagate SATA 7200rpm, Windows XP SP1, ATI Catalyst 5.2.

Testing software will consist of the following:

SiSoft Sandra 2004 Memory - Our standard synthetic test to establish a baseline.

PiFast - A good indicator of CPU/Motherboard performance is PiFast version 4.2, by Xavier Gourdon. We used a computation of 10000000 digits of Pi, Chudnovsky method, 1024 K FFT, and no disk memory. Note that lower scores are better, and times are in seconds.

Quake 3 - While it's old and moldy, it still has some value as a system level benchmark.

The comparison memory will be Corsair's 4300C3PRO clocked at DDR2-533 @ 3-2-2-8, and at DDR2-667 @ 3-3-3-8, which were the best we were able to manage while passing the R.S.T. Pro2 tests. The memory in the charts below are to be read: Model - Timings - DDR2 speed.

SiSoft Sandra 2004 Memory

No surprises here as we see the performance scales proportionately with the clock speed and timings. Given Corsair's ability to run at slightly better timings, we can see the slight performance edge at DDR2-667.

PiFast

Some improvements can be seen in PiFast as we go up in clock speed. Again, at DDR2-533 there us little difference, but the Mushkin PC2-4200 does hold down the fort. At DDR2-667, Corsair holds a small lead.

Quake 3: Arena Demo Four, Min Detail @ 640

Mushkin's ram grabs the pole position at DDR2-533.

Final Words

As we've seen with Corsair's low latency DDR2 kit, when you're limited at DDR2-667 and lower, memory timings can have a significant impact on overall performance. While higher frequency ram kits still show performance increases as we hit higher clock speeds, there are not many 915/925 setups that can follow. It really isn't worthwhile looking at those kits as all you end up doing is down-clocking the ram.

Compared directly against the Corsair TWIN2X-4300C3, which will be Mushkin's PC2-4200's direct competition, neither module holds a distinct edge over the other. At DDR2-533, the results are mostly in Mushkin's favor, but not by much. At DDR2-667, our Mushkin sample was not able to run at 3-3-3-8, and thus Corsair holds the crown here. Keep in mind we only chose to run the modules at the speeds that passed R.S.T. Pro2. Our sample can in fact run at DDR2-667 at 3-3-3-8, but it was not always stable and it did fail the R.S.T. Pro2 test.

We were quite pleased with Mushkin's PC2-4200 3-2-2-8 as it performed reliably and was quick as well. We did hit some hurdles in overclocking past DDR2-667, but in that case you would be better served by their PC2-5300 kit. Other than that, Mushkin doesn't package the bling such as flashing LEDs, but in turn their ram modules are easier on the wallet. Backed by an amazing lifetime warranty, we have no problem recommending this kit if you're a 915/925 owner looking for good quality ram.

Pros: Very fast, good overclocker, reliable, lifetime warranty.

Cons: Struggles to overclock past DDR2-667.

Bottom Line: If you own a setup capable of some decent overclocking, the PC2-4200 3-2-2-8 is a very solid choice. We would still lean towards default DDR2-667 (and up) if you're building a 925XE system, but even then the PC2-4200 would be a decent pick if either you cannot or choose not to overclock past DDR2-667.