1 slow core on prime 95 q9550

B

boonet

New Member
Hi

When i oc'd my cpu to about 3.865 ghz, i ran prime 95 and i noticed worker 2 (on physical core 1) was working like 10 times slower then the other ones.

Is this maybe because windows vista tries to lock the working programs to 1 core when the others are fully used by prime ( in this case)?

When i put the settings back to default, this was again the case but a lot much noticeable ( but this time on core nr 2 of 3), and it ran on a much lower temp then other 3.

So does vista lock working programs who doesn't need much cpu to 1 core causing 1 worker on prime 95 to slow down, or is it because i have a bad cpu.

Thx boonet

specs

P5Q pro
q9550 @ 3.865
8 gigs dominator
750 w corsair psu
eah 4870X2
some hdds
scythe mugen 2
antec 1200
 
Hi Boonet, our setup is very similar..nice choice! :)

Your gut instinct may well be correct, to prove it try running prime 95 on safe mode where your normal vista programs aren't running on the background and see the difference.
 
this evening i'll surely do that, afterwards i have another question, what are your settings to achieve 4 ghz and is it stable? im now at 3.8 stable, but i cant get the 4 ghz large fft test stable...
That bios u have, is it a newer version than the one on mine? I have marvell 1.1.00 or something like that. were can i download it, and how do i have to install it?

I cant imagine i finally found someone with almost identical rig as mine!!!!


thx boonet
 
Yeah that sounds about right. Other programs are still running and need use a one core to do their thing, which would explain why prime95 is running slow on that one.
 
Hi Boonet, I got to 4ghz by spending a lot of time tweaking my bios settings then running prime 95 for a minimum of 7 hours.

To get your q9550 to 4ghz, you may need a different setting completely, even if on the surface our rigs looks the same.

The first thing you need to check is what stepping version your q9550 is. There are 2 versions a C1 stepping and an E0 stepping, the 2nd one being the latest version and easier to get to 4ghz without too much trouble.

Run CPU-Z and on the first tab check under revision if it's E0 or C1

Also find your CPU's vid, download CORE TEMP and it will say under VID.

To check your bios version, on CPUZ it will be under the mainboard TAB. You can download the 1406 bios from the Asus website.

What is your ram spec?
 
yeah i read this tutorial on how to overclock (http://www.ocforums.com/showthread.php?t=515316), im still trying to get it right, my stepping is C1, i know its not as good as E0 but i will try to get it to 4 ghz. Ram is 8 gigs of dominator at 1.066 ghz

my vid is 1.2250V, however i set my cpu voltage to 1.37500 in the bios. Is this the famous vdroop?

Ill download the new bios because i have the 1306.

Can you give me your bios settings for me to know were to start?

thx boonet
 
Hi Boonet, that's a good guide.

I think you're nearly there. I don't think it's the vdroop, it's more likely your voltage combination. Plus vdroop can be treated by enabling 'load line calibration' depending on how much voltage fluctuation you have, leaving it disabled isn't bad)

Try this setting for your setup:

CPU Ratio - 8.5
FSB Frequency - 471
FSB Strap - 333
PCI-E Frequency: 100
Dram Frequency - choose the lowest setting out of the 3 (for now)
Dram Timing Control: Manual
Try 5, 5, 15 and leave everything on auto

DRAM Static Read Control -Disabled
DRAM Read Training -Disabled
MEM OC Charger - Disabled
CPU Volt - 1.39 (start with this voltage for now..if unstable increase the voltage slowly)
CPU PLL - 1.5
FSB Termination Voltage 1.26
DRAM Voltage - 2.1
NB Voltage - 1.4
SB Voltage - 1.2
Load line Calibration - Disabled
CPU Spread Spectrum - Disabled
PCIE Spread Spectrum - Disabled
C1E - disabled
Max CPU ID Value Limit - Disabled

Prime95 it for 2 hours initially and let me know your temps...
 
ok thx, isent the vcore to much? isnt it over the recommended of intel?
its for 24/7 use, (not always up, but i just want to be able to use this oc always, not needing to go back to other settings because i know i otherwise will fry my cpu in less then 2 years)

thx boonet
 
Hi Boonet, don't worry
0.85V – 1.3625V is the average expected VID (voltage identifier digital) to pass through the chip on stock settings. :)
 
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ok now i get it, so max vcore is 1.45.
i updated to latest version of bios, tomorrow ill use youre settings...

thx alot friend...
boonet
 
hmmm, help me on this one: no matter what i do to the vcore, it prime still stops with 1 error after 2 secs or somthing, i enabled my load line callibration, otherwise my vcore went from 1.39 to 1.28 and stuff like that. Now my vcore in the bios is at 1.4125 somthing like that but i doesnt matter if i pick this vcore or 1.36875, it still crashes within 2 seconds. i already upped my nbvolt, sb volt, vtt volt.. (Oh yeah its always core 0 or 1 that crashes)... nothing helps? what should i do?

boonet
 
Boonet, keep the other settings the same as before. Just change the vcore to 1.425 and cpu pll to 1.56 then prime it..

Also what are your load temps?
 
the more vcore i put trough the faster it gives an error? now its instantly when on vcore 1.425 and themps are 85-85-74-75 when in small ffts ( large won't last long enough to watch the temps :S). I put evrything like u did, only changed the vcore

wtf is going on here?
 
Temps are too high for cores 1 and 2, drop the vcore to 1.4

Let's check your FSB overclock - drop the cpu multi to 8, so it's 471 x 8 then prime it
 
hmmm ok i think i misplaced my cooler... ill need to mabe lap it or somthing like that.
but ill lower the vcore and the fsb then see what happens..

thx
 
this doesent help.... maybe a fault of ram??
whatever i do, it keeps crashing after a sec or two...??
temps: 68-68-61-60
 
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