Overclock issues with Q9550/RAM at 1066!

Sweetloaf

Sweetloaf

Sweetloaf

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Joined
5 Mar 2004
Posts
6,399
Location
Southport
Main Specs:

Q9550
OCZ Reaper PC-8500 (1066)
MSI Neo 3-- something something :)
Corsair 650W jobby

The Q9550 sits quite happily priming at stock volts @3.4Ghz (8.5x400) with the RAM running at 800Mhz

Likewise if I change the RAM divider and run the Q9550@stock with the RAM set to 1066Mhz it primes quite happily.

However if I try to run the CPU at 3.4Ghz and the RAM at 1066 simultaneously the PC will go into an odd boot loop and after about 5 loops gives me an overclocking failed message. I have occasionally got to the point where I select which OS to load (running XP and 7) and run the memory checker which shows a hardware fault after about 30 secs.

It seems odd that the CPU is stable @3.4Ghz and the RAM at 1066Mhz unless I try both at the same time:confused:

RAM is manually set to 2.1v when I try it at 1066.

Any suggestions? It's been a while since I've mucked about with any overclocking and it's amazing what you forget :)
 
Might be worth upping the northbridge voltage a bit. I had to up mine by 0.2v to get 4 sticks stable.
 
Most likely you are setting the RAM speed incorrectly.
The 1066 setting is based on what the stock FSB of 333 or your OC of 400 ?
Do the math your likely running your RAM well over 1066 when using 400FSB.

Do you have ratios like 1:1 4:5 etc or fixed settings like 666, 800, 1066

Also set the strap correctly if you have that setting in your BIOS.
 
PCZ said:
Do you have ratios like 1:1 4:5 etc or fixed settings like 666, 800, 1066

Also set the strap correctly if you have that setting in your BIOS.
Click to expand...

I've change the ratio to ensure it runs at 1066.

Should it really be necessary to increase the CPU voltage if it primes at 3.4Ghz when the RAM is set to 800Mhz?

I will try increasing the NB volt a little to see what happens, had a quick look last night though and it wasn't obvious which setting to adjust, anyone know what it's called? :)

CPU-Z also recognises my RAM as 6400 and only lists JEDEC speeds up to 800, does this mean I may have to manually adjust timings? I thought I had checked timings and they were correct when running the CPU @ stock.
 
Sweetloaf said:
I've change the ratio to ensure it runs at 1066.

Should it really be necessary to increase the CPU voltage if it primes at 3.4Ghz when the RAM is set to 800Mhz?

I will try increasing the NB volt a little to see what happens, had a quick look last night though and it wasn't obvious which setting to adjust, anyone know what it's called? :)

CPU-Z also recognises my RAM as 6400 and only lists JEDEC speeds up to 800, does this mean I may have to manually adjust timings? I thought I had checked timings and they were correct when running the CPU @ stock.
Click to expand...

Upping the cpu voltage slightly would factor the cpu out of the equation. So you wouldn't have to worry about cpu instability being the culprit. By increasing Ram speed to 1066Mhz, the data is being transferred faster between Ram and cpu and it may be that there isn't enough cpu voltage for cpu to process data smoothly at 3.4Ghz. In other words [email protected] is being worked harder at 1066Mhz ram speed than at 800Mhz. Imo in overclocking anything could give rise to instability.

As for NB voltage, it should be MCH (Memory Controller Hub) voltage
 
Good news! Manually set the timings to 5/5/5/15 trFC 54 and everything is now hunky dory, RAM and CPU both seemed happy! Just an oversight on my part!

This has given my some nice headroom and I'm now priming at 3.6Ghz with RAM@ 1016 and asking for more! I'd forgotten how much fun this was when everything works :)

Thanks all!

edit - With a different ratio setting, now @ 3.64Ghz and 1067Mhz :D
 
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