CAS2 PC3200 or CAS 2.5 PC3500

I am on the verge of ordering memory for a new project. Likely newegg 2100+ and EP-RDA8. I want to obtain the highest realistic memory throughput so I am planning on using 2 sticks of 256MB corsair. Now which memory will likely give me the higher fsb at CAS 2 with aggressive timings?

Thanks

Yo

There is no guarantee as to which memory will do that but I would go with PC3200 if I were you, because you can run your FSB at 200 and your memory in sync, and it is already guaranteed to do that (400mhz) in cas2 so you got nothing to lose. It's not guaranteed to do it with aggressive timings but If you get good memory like corsair it probably will.

Corsair has some new low latency memory that will do aggressive timings guranteed at 200 or 217 mhz

Thank you for the response. I am aware that I should be able to reach 200MHz at CAS2 with the LL-PC3200, but I am also expecting that from the PC3500, since it should have some headroom.

I am actually hoping for more than 200 MHz at CAS2 and that's where the choice becomes somewhat difficult...

Yo

I think the big problem with majority of the NF2 boards trying to run Dual Channel DDR over 200FSB is the lack of voltage for the chipset. There are VMods instruction for these boards floating around the web already.

If you aim beyond 200 MHz FSB, I'd go with Corsair 3500C2 which is spec at 6-3-3-2 memory. Other memory like Kingston HyperX 3500C2, OCZ 3500C2, ... are spec at 8-4-4-2 timing, which may not be able to run at DDR 434 MHz at 6-3-3-2 due to module variations.

For bandwidth benchmarking, 3500C2.5 @434 MHz DDR would score higher than 3200C2 @400 DDR. 3500C2 is about 9% faster than 3200C2, and 4% faster than 3500C2.5. So 3500C2.5 would still be faster than 3200C2 by a few %. It will lose a bit on latency when the processor has to get data from memory if there are lot of cache miss.

I am in similar situation, looking for running at 230+ MHz FSB, at which even Corsair 3500C2 may not have enough headroom to do that. I am waiting for 3700C2, but don't know how long the wait is. Samsung, OCZ and GEIL have 3700C2.5 memory for that speed, but I am not sure they will be able to deliver x-3-3-2 timing at 2.8 V, unless you want to boost the Vmem to try.

I have been very impressed with my Corsair XMS PC3200 C2. Right now it is running at 217 MHz sync at 6-3-3-2.0. I have had it at better timings but super pi wouldn't run with stability.

With my XMS3200C2 I've managed to get 216Mhz with 2.0-6-3-3 @2.7V and 221Mhz with the same timings but @2.8V. Highest i can go is 230Mhz 2.5-6-3-3 @2.8V. 200FSB i can run 2.0-5-2-2 with 2.7V.

Thanks for the replies - I went with a pair of the cas2 3200. I have the feeling that they may both be using the same chips and simply market it differently, because PC3200 cas 2 has fsb headroom and PC3500 cas2.5 may have cas headroom at slightly lower frequency. We'll see - I'll keep you posted.

Yo