2.8E can't reach 3.5ghz. PC4000 RAM the way to go?

[Optimummind]

My Prescott 2.8E is currently overclocked to 3.4ghz with a FSB of 243. The CPU voltage on the Abit IS7 is 1.6625 V. The DDR voltage is 2.6V on my 2x512mb PC3200 setup. (1x512mb is a no-name Legacy brand and the other 1x512mb is a Mushkin value brand).

Through the BIOS, the 2x512mb DDR400 is running at 2.5-3-3-7 with a 5:4 ratio speed of 194.7mhz (194.7mhz x 2 = 389.4mhz effective).

I've tried to reach a stable 3.5ghz (FSB=250mhz) but running 3Dmark05 causes WinXP to BSOD. I've tried increasing the CPU voltage to 1.7125 V but it's doesn't help. I've tried loosening the memory timings to 3-3-3-8 but oddly, this caused a failure of WinXP to load (whereas booting the system with 2.5-3-3-7 at least got me to a stable Desktop).

What do you think is holding me back? BTW, the CPU is being watercooled by the Koolance CPU-200G and with AC in my room, the temp is around 46 to 47 C.

Will buying the Geil Ultra PC4000 DDR500 ram help me to reach a stable 3.5ghz or have I already reached the limit of my CPU overclock? I don't want to invest around $150 on the Geil PC4000 and find out that I still can't overclock to 3.5ghz.

All help/advice/feedback is greatly appreciated!

 

[Acanthus]

I would say that memory will not help.

Also, your CPU voltage is awfully high.

You are either reaching the limit of the chip (being a 2.8E i would believe it, my 3.0E tops out at ~3.71ghz) or the fsb limit of the motherboard. Does the IS7 have AGP/PCI lock? You could also be running AGP too far out of spec.

 

[Optimummind]

Yes, I've set the PCI/AGP lock through the BIOS.

Does anyone else think I shouldn't buy the PC4000 RAM?

 

[Optimummind]

Just for future reference, which mobo manufs have the most high and reliable OC ability?

 

[Acanthus]

Originally posted by: Optimummind
Just for future reference, which mobo manufs have the most high and reliable OC ability?

DFI, hands down.

But many motherboards are limited by the chipset itself, not design flaws. Typically DFI boards overclock the highest, and are rock solid.

All the best OCing boards for Intel are DDRII unfortunately, im unwilling to pay the premium for no performance increase at all, when i could easily jump ship and go AMD and have better gaming performance for the same money.

 

[Optimummind]

I was thinking about jumping ship to AMD for my next upgrade as well. The ULI M1695 chipset with the southbridge that supports AGP8x sounds pretty nice. Now, only if Asus or Abit can make boards soon. =)

 

[Bona Fide]

If you're gonna switch to AMD, at least wait for Crossfire and the new ATI chips to make their debut. If they're a hit, go with the Crossfire chipsets. If they're a flop, go with the ULI.

 

[Acanthus]

Originally posted by: Bona Fide
If you're gonna switch to AMD, at least wait for Crossfire and the new ATI chips to make their debut. If they're a hit, go with the Crossfire chipsets. If they're a flop, go with the ULI.

I dont trust ATi chipsets yet, and ill prolly just keep my 6800GT for another generation.

 

[Optimummind]

Originally posted by: Bona Fide
If you're gonna switch to AMD, at least wait for Crossfire and the new ATI chips to make their debut. If they're a hit, go with the Crossfire chipsets. If they're a flop, go with the ULI.

Well, I'm not interested in Crossfile or SLI. I also want to keep using my AGP 6800GT for a bit longer until I see a 32 pipeline part from nVIDIA. That's when I'll make a jump to PCIe x16 GPUs.

Hopefully by early 2006, the prices on the A64 X2 4400+ CPU's will be down to around $350-400.