a64 3000+ oc issue

[imported_asfd]

My previous rig: a64 3000+ 754 newcastle, 2x256Mb crucial pc2100 ram, mobo Asus k8n w/ nvidia-250 chip. I oc CPU to 220 fsb x10 = 2.2 Ghz, ram to 148hz (ram:cpu = 2:3), which runs pretty stable, and passed prime95 on 12 hours mixed testing.
My current rig: only replaced the ram with one 512mb crucial pc3200, and oc the ram to 220hz (ram:cpu = 1:1), . However, I cannot pass prime95 anymore, it even fails after 1 minute. First I thought it could the ram issue, but after run memtest86 for 15+ hours, not a single error.
I am totally confused, why my oc cannot pass prime95 any more after upgrading ram? any idea? TIA.

 

[bfonnes]

running your RAM at 220 HZ it sounds like underclocking to me I suppose it could be power related...
What power supply is on your machine? and anyhow going from 148 to 220 is a pretty big jump. You make it sound as if it is just a few Mhz and should be no big deal.

bfonnes

 

[imported_asfd]

220hz is underclocking? yep, I know what you mean , typo, should be 220mhz, right? ok, my psu is antec true430, drives 2 HDs, 1 DVD writer. Thank you, bfonnes.

 

[bfonnes]

ok, I am not an expert or anything, power could be fine, but I think you might have to raise the voltage on your memory sometimes to get higher overclocks
bfonnes