I installed another 2 gig of RAM and it wrecked my overclock. Why?

Shrapnel · 22 Dec 2006 at 10:29

Hi all.

I have 2x512 of TwinMos Ram. I'm overclocking the CPU (A64 3700) to 250Mhz , and the RAM is at 196Mhz.

I installed another 2x1Gig of Corsair Ram rated at 218Mhz. (DDR3500). But, this stopped my overclock from working. I restored to stock speeds, went into Windows and the RAM was running at 100Mhz (CPU/23). What caused this?

I removed the old 1 gig stuck and can now run back at 250Mhz so that's good. BUT, my super_Pi time for 1M has increased from 32 Secs to 34 seconds. Why is this?

Thanks.

pegasus1 · 22 Dec 2006 at 10:36

Shrapnel said:
Hi all.

I have 2x512 of TwinMos Ram. I'm overclocking the CPU (A64 3700) to 250Mhz , and the RAM is at 196Mhz.

I installed another 2x1Gig of Corsair Ram rated at 218Mhz. (DDR3500). But, this stopped my overclock from working. I restored to stock speeds, went into Windows and the RAM was running at 100Mhz (CPU/23). What caused this?

I removed the old 1 gig stuck and can now run back at 250Mhz so that's good. BUT, my super_Pi time for 1M has increased from 32 Secs to 34 seconds. Why is this?

Thanks.

Ditch the 2x512 and just run the 2 gigs
See what the max fsb that RAM will go to, if its around 230 then you can drop your multi to 10 and run a higher FSB (making your mem bandwidth higher).

weetabix · 22 Dec 2006 at 11:06

pegasus1 said:
Ditch the 2x512 and just run the 2 gigs
See what the max fsb that RAM will go to, if its around 230 then you can drop your multi to 10 and run a higher FSB (making your mem bandwidth higher).

Yeah you cant expect a good overclock with 2 different types of ram, since they will both need optimal timings, which is why your pi time is slower, because either you have them on auto settings and theyre running at different timings or perhaps the memory has a higher access time, and you need to tweak the settings a little(lot probably). I doubt youre thinking the 2GB would help pi 1m, but since it only uses 8mb..it wont

Shrapnel · 22 Dec 2006 at 12:20

cheers guys.

No - I wasn't thinking the extra RAM would help the timings, but I didn't think it would slow the calculation by 2 seconds!

I run the RAM at 196Mhz, but why would I now be able to run all 3 gig at that speed?

FreeStream · 22 Dec 2006 at 13:22

Shrapnel said:
cheers guys.

No - I wasn't thinking the extra RAM would help the timings, but I didn't think it would slow the calculation by 2 seconds!

I run the RAM at 196Mhz, but why would I now be able to run all 3 gig at that speed?

AMDs memory controller can only handle 4 double sided sticks at 2T. Your running 2 different size sticks aswell as types.

Ditch the 2x512Mbs and get the mem back to 197mhz and to as tight timings as possible!