Overclocking CPU on abit is-7

[Tenstorey]

Processor 2.8 pentium 800fsb
1 GB twinmos 3200 duel channel
Motherboard ABIT IS7-e (latest BIOS)
Hi,

I've been dabbling in slight overclocking of my system (2.8 to 3.0Ghz) but I've been running into problems with my RAM. When I overclock the FSB more than 3 or 4Mhz I begin to notice arifacts in some 3D applications (shearing of textures). When I cranked this up to a 14Mhz O/C (CPU@2.99Ghz) and ran 3DMark04 I noticed the same flaws on the CPU only tests. (I was having problems with artifacts on stock speeds but I managed to fix this by relocating the RAM on the motherboard). reducing the DRAM ratio to 5:4 prevents problem so obviously my RAM runs very tight on duel channel in my motherboard. I've also tried uping the voltage from 2.6 to 2.8v and slacking the memory timings but this does not make a difference.

My question is is it better to run the ram at the 5:4 ratio with the CPU@3.0Mhz or will this degrade performance to the point the Overclock is being undermined greatly by a slow a ram speed? Also I'm running the CPU on stock cooling and wondering if this is a safe O/C at this setting. I do have Motherboard monitoring running in the background which should give me warning of excessive CPU temps.

The main reason for the O/C is that I have reciently purchased a 6800GT graphics card and don't want to hold it back too much.

Thanks for any help.

Craig

 

[Corporate Thug]

that is a very conservative OC. you may want to try to run memtest to test the ram and make sure it has no errors. also, try loosening the timings

 

[Tenstorey]

I ran a memtest when I was having the same type of error when the RAM was in different slots on the motherboard. The memory checked out fine yet the graphical glitches were present. What I don't understand is that if the ram is producing errors they would windows (I run xp btw) not crash periodically? I'll take another look at the timings and run another memtest.


Thanks

Craig

 

[Corporate Thug]

the errors can be small enough not to cause a crash but give problems when it is stressed (like in a 3d environment)

 

[Tenstorey]

I just ran memtest with the RAM running of a 214mhz FSB and there were a number of error cropping up so it seems its very stricly timed at the default settings. I'll slack the timings, increase the voltage and re-test but it looks like its poor RAM I have.

If this is the case I'll buy new RAM but until I do that would running a 5:4 ratio @3.0Mhz (214fsb) have a large impact on the computers performance? I would guess that the memory would be running at around 171Mhz with this so it is quite a drop from 200Mhz. (Perhaps I could get away with a bigger CPU overclock?)

Thanks

Craig

 

[cbehnken]

I have twinmos 3200 in my A64 and it runs 240 Mhz at 2.6 volts and passes memtest. Are you sure your agp bus is in spec?

 

[Tenstorey]

Running memtest would bypass the AGP bus anyway plus the glitching error appears on the 3DMark CPU tests when overclocked. The problem may be that my motherboard is not too friendly running duel channel with my RAM.