IBT

paradisiac · 22 Jul 2011 at 10:32

joeyjojo said:
Graphics card?

Seriously that's pretty surprising.

dropped back to 4.6GHz and crysis ran for well over 2hours so i would say that it just wasnt quite stable @ 4.8GHz.
im not too bothered as i didnt spend a lot of time tweaking the oc so its probably something i overlooked.

Plec · 22 Jul 2011 at 12:29

joeyjojo said:
Seriously that's pretty surprising.

It's 'par for the course' Joeyjojo when pushing for the maximum clock from a CPU.

Not everytime, granted, but enough not to class a CPU stable untill it's run for a few days/weeks with normal usage without a BSOD.

You don't experience it so much with moderate clocks - but when pushing a CPU to its limit - then stress testing alone will not always find all a clock's weaknesses.

As mentioned previously some CPUs can pass all stress tests you throw at them and then 'trip over' with day to day usage.

I know it's hard to comprehend - especially when it's passed 20 runs of IBT (50 in this case) and 24 hrs of prime etc - only to then BSOD with light apps use. It can be infuriating...

However, if you look at 'day to day' usage as the final stress test - it's not so dissapointing when it happens.

@ Parasidic - 4.GHz is a great clock and you may yet be able to tweak 4.8GHz.

paradisiac · 22 Jul 2011 at 12:38

Plec said:
It's 'par for the course' Joeyjojo when pushing for the maximum clock from a CPU.

Not everytime, granted, but enough not to class a CPU stable untill it's run for a few days/weeks with normal usage without a BSOD.

You don't experience it so much with moderate clocks - but when pushing a CPU to its limit - then stress testing alone will not always find all a clock's weaknesses.

As mentioned previously some CPUs can pass all stress tests you throw at them and then 'trip over' with day to day usage.

I know it's hard to comprehend - especially when it's passed 20 runs of IBT (50 in this case) and 24 hrs of prime etc - only to then BSOD with light apps use. It can be infuriating...

However, if you look at 'day to day' usage as the final stress test - it's not so dissapointing when it happens.

@ Parasidic - 4.GHz is a great clock and you may yet be able to tweak 4.8GHz.

im 99% sure if i upped the vcore to 1.4-1.41 it would be stable, and probably go up to 5GHz, but i dont want to take that chance.
4.6GHz is good enough for me, so will fiddle with that to get the lowest 'stable' vcore and temps at that

betaspin · 22 Jul 2011 at 12:54

paradisiac said:
ok, well it did the 50 runs of IBT fine, a good 5hours+ of prime, loads of benchmarks and ran ok for general browsing, office etc. 5mins into crysis and BAM!!!! locked up.

Perhaps the +12V rail has problems coping with the combined CPU+GPU load? Always worth checking with the OCCT psu test.

joeyjojo · 22 Jul 2011 at 15:22

Thanks Plec, you may well be right.

betaspin said:
Perhaps the +12V rail has problems copying with the combined CPU+GPU load? Always worth checking with the OCCT psu test.

I find this far more likely though. I don't believe it's possible a system will pass IBT, then BSOD at idle/day to day usage.

Our friend has in his sig "700w Modular PSU". It's probably a no name brand and can't provide the amps.

paradisiac · 22 Jul 2011 at 15:25

joeyjojo said:
Thanks Plec, you may well be right.

I find this far more likely though. I don't believe it's possible a system will pass IBT, then BSOD at idle/day to day usage.

Our friend has in his sig "700w Modular PSU". It's probably a no name brand and can't provide the amps.

yeh its an evolabs so might well be the case

but it seems ok at 4.6GHz so it will stay there until i get problems. i will eventually upgrade my PSU when the new batch of gfx cards come out.

joeyjojo · 22 Jul 2011 at 15:27

I'm not an electrician, but the side of the PSU usually says the current output for each rail. If you post a photo we should be able to figure out if it's the PSU.

paradisiac · 22 Jul 2011 at 15:37

not sure if thats good enough to read.

joeyjojo · 22 Jul 2011 at 15:41

Looks like 30 amps on 12V rail - is that sufficient OcUK wise guys? For 2500K @ 4.8 and crossfire HD6850s.

P.S. Nice rig

paradisiac · 22 Jul 2011 at 15:44

joeyjojo said:
P.S. Nice rig

cheers, looks nicer with the gfx cards fitted

have to strip it back down on sun/tues to work out my slow boot issue.

betaspin · 22 Jul 2011 at 15:46

paradisiac said:
yeh its an evolabs so might well be the case but it seems ok at 4.6GHz so it will stay there until i get problems. i will eventually upgrade my PSU when the new batch of gfx cards come out.

While in Crysis 2 can you hear the PSU fan turning way faster, and is it exhausting way more hot air? What happens under a combined CPU+GPU load is that the insides of the case get much warmer, and if some of this air is exhausting through the PSU, it gets hot and its efficiency decreases. When the PSU is on the limit, this may lead to a problem.

paradisiac · 22 Jul 2011 at 15:49

i was playing crysis not crysis 2, but i cant say i noticed anything getting louder, but then on the whole with all the fans its pretty loud to start with.

but..........

the air is sucked in from outside the case (fan on bottom of psu) and out the back, so no internal air should pass through the psu.

joeyjojo · 22 Jul 2011 at 15:51

Bit tech says those cards pull 230W each. If the chips doing 160 that's 620W, which is getting close to max.

This says each card pulls 10.2 amps. If they're overclocked it could be higher. Seems reasonable to assume you need a beefier PSU.

paradisiac · 22 Jul 2011 at 15:54

joeyjojo said:
Bit tech says those cards pull 230W each. If the chips doing 160 that's 620W, which is getting close to max.

This says each card pulls 10.2 amps. If they're overclocked it could be higher. Seems reasonable to assume you need a beefier PSU.

under full load my british gas wattage reader thingy says my psu uses around 500-600w so i suppose that is very close.
i could swap it out for the 800w model, but will that not still have the same ampage?

betaspin · 22 Jul 2011 at 15:55

From the label I think that you have two 30A 12V+ rails, but there should be some additional restriction as 2x30x12 = 720W which is more than the rated power. All depends on how the connectors are distributed b/n the rails. If the CPU, one of the graphics cards, the motherboard, some hard disk and fans are all one rail, this could cause problems, as 360W is not that much.

paradisiac · 22 Jul 2011 at 15:56

its a modular psu, so obvs everything has its own rail on the outside of the psu, but im not sure what goes on inside the unit

joeyjojo · 22 Jul 2011 at 15:58

^ Do you mean using different connectors could spread the load? As it's modular.

betaspin · 22 Jul 2011 at 15:58

paradisiac said:
i was playing crysis not crysis 2, but i cant say i noticed anything getting louder, but then on the whole with all the fans its pretty loud to start with.

but..........

the air is sucked in from outside the case (fan on bottom of psu) and out the back, so no internal air should pass through the psu.

Crysis is not that demanding as Crysis 2 with DX11, but still...

Sorry, had not seen the picture, so the warm air is not a problem.

If going for a stronger PSU, read the ratings of the 12V+ rails and try to find out the distribution of the connectors b/n rails.

betaspin · 22 Jul 2011 at 16:00

joeyjojo said:
^ Do you mean using different connectors could spread the load? As it's modular.

No, different external connectors can go on the same rail internally. One needs to see the connection diagram that usually comes with the documentation.

paradisiac · 22 Jul 2011 at 16:01

it would have to be the 800w version of what i have (although on that one it now states its a revised model with i1/i7 support) until nearer xmas when i do my next big upgrade.