Overclocking my 5850 and phenom II 955

[Reliablesand]

Hi all.

 

After building a new system from scratch I'm investigating my overclocking potential. Here's the system:

 

CPU: AMD Phenom II X4 955 Stock 3.2ghz Cooled with a Thermal Take V1

RAM: GSKILL 2x2GB DDR3 1333

VIDEO CARD: Sapphire Radeon 5850

MOTHERBOARD: GIGABYTE GA-MA770T-UD3P AM3

POWERSUPPLY: Rosewill Green Series 530W

CASE: APEX Vortex 3620 SGCC case w/ 2 120mm fans (one at front and back sucking air in for positive pressured case

 

Here is what I've achieved so far:

 

-CPU temps 28C idle maxed so far at 58C under load (3dmark Vantage trial run, twenty minutes of Crysis)

-Video card overclock of 800mhz/1190mhz at stock voltage with temps maxing at around 75C (most stable, but not thoroughly tested for stability, when running higher computer will hard crash with either a gray or beige color screen that requires reset. I'm aware of an issue with 5850's involving a HDMI sound driver but I'm not sure if this is why. Of other note, 3dMark Vantage trial run at CCC maximum allowed OC seemed stable but no real stress test has been done. Voltage hasn't been raised at all as I'm unsure I know enough to be smart about it so this could account for the crash as it seems other sites who've clocked the card higher did increase the voltage)

 

What I'm unsure about:

 

-My CPU temperatures don't seem very good to me if I'm going to try and overclock. So far I've only seen it max at 58C under load but I don't know if that is the highest it will go yet. My cooling method may be considered lax by some but there are plenty of ventilation holes along the entire front of the case and on the side panel. According to other posts and the review of the 5850 at Guru3D these temps aren't out of the ordinary. Are my temperatures too high for overclocking the CPU and GPU?

 

- Review sites for the 5850 recommended a PSU that had at least 500W and 40 amps on the 12volt. My PSU is specced to have 41.5 amps available on the 12volt. When initially setting up I plugged the 2 120mm fans into the main board but noticed the rear fan didn't spin up on its own volition. After plugging both fans through an adapter to the 4pin connectors on the PSU this issue went away. I don't know if I'm underpowered on the pSU or if the Motherboard just couldn't deliver the juice. In the end I want to know if overclocking a graphics card will require more power in the end. So far other posts have suggested that the 5850 is a very low power consuming video card in its class, and Guru3d's recommended minimum power supply also seems to account for a 870mhz/1225mhz overclock, though I don't know if they increased voltages or not. To make a long story short, is my powersupply strong enough for this build and is there enough juice to start overclocking?

Edited December 20, 2009 by Reliablesand

[GodlyManDude540]

have you tried reseatting your cooler?

And hot air will build up in your case so i would suggest having your rear fan be an exhaust fan

Edited December 20, 2009 by GodlyManDude540

[Reliablesand]

have you tried reseatting your cooler?

And hot air will build up in your case so i would suggest having your rear fan be an exhaust fan

 

Will that require re-applying paste?

 

I was wondering about it because after I got the thing settled in I noticed that the heatsink overlapped the edge of the processor heatspreader by a fraction. Like half a millimeter. It was such a bother to get installed that I decided to see where it would go with it.

 

I can flip the rear fan to act as exhaust if I need to. I'll have to flip the heatsink anyway if I do so it actually blows out the rear exhaust. Right now it blows out the front because the front of the case if filtered mesh and I have the cables in the case pretty well out of the way.

[insan3]

58c is pretty damm hot for stock setting on the cpu. my 955 OC at 3.8 doesnt even hit that. i am going to say its because of ur case; it doesnt have HAF.

[rourkchris]

I think your CPU cooler isn't up to the task.

[Crazy_Nate]

I was getting 51C full load (linpack) with the STOCK Phenom II 955 cooler...something is wrong if you're getting temperatures like that without overclocking.

 

You're going to want one fan intake, one exhaust. It'll be a little negative pressure inside, however, you'll have better airflow. Even better yet would be two intakes and one exhaust, with the power supply exhausting as well.

[insan3]

today is ur lucky day i am selling my CM v8 but i am pretty sure it wont fit on ur case. i dont think ur case would raise temps by 15c . what u need to is re-sit ur cpu -cooler with some new thermal paste. if that doesnt work then u need a new cooler.

[Reliablesand]

Well I got good news. I went ahead and ditched the positive pressured case approach and flipped the rear 120 to act as exhaust. I also re-set the heat sink and aimed it to blow air at the rear exhaust. I went ahead and ran the crysis benchmark a couple times and was glad to see temperatures not rise above 42C. I also took the little speed adjuster that came with the heat sink but I'm not sure that did all that much.

 

The computer is quieter and cools better. I'm trying to find a working download for prime95 but have had little luck as well as an unhelpfully dodgy internet connection. Glad to see temps are better though.

 

I'm thinking that I may be limited with overclocking by the powersupply though. Its within recommended spec but I didn't go out of my way to make sure it was far over acceptable limits. There is one thing I'm unsure of though. Will a CPU or GPU draw more power when overclocking if they are left at stock voltage?

[insan3]

yes it would draw more power if you set it to. depends on the overclock.

 

for example: the 955 comes at 3.2Ghz with vcore at 1.35, i have mine OC at 3.5 with vcore at 1.35.

but if i set it to 3.8 i need 1.50 vcore

 

u dont need a beefy psu to OC a cpu. for GPU is different. your psu is enough for ur cpu

Edited December 21, 2009 by insan3

[Reliablesand]

yes it would draw more power if you set it to. depends on the overclock.

 

for example: the 955 comes at 3.2Ghz with vcore at 1.35, i have mine OC at 3.5 with vcore at 1.35.

but if i set it to 3.8 i need 1.50 vcore

 

u dont need a beefy psu to OC a cpu. for GPU is different. your psu is enough for ur cpu

 

Good to hear. So as I understand it not adjusting the voltage will not cause a cpu to draw more power when overclocking. Only when you adjust the voltage to obtain higher overclocks does more power consumption become a factor.

 

Does the same apply to the video card? will more power be drawn if the voltage is kept at stock but the core and memory are dialed up?

 

Further that, while stressing the range of my video card overclocking capability I reached a point at aroun 810mhz core and 1200mhz memory at stock voltage when I would have a crash in the form of a lock up that required hard reset or a solid color displayed on screen (gray, beige, multicolor, I've never seen a crash screen like it before) Do you believe this is likely a power draw issue from the PSU or a lack of power to the video card because of the stock voltage?

[insan3]

ur lacking power to ur video card. so if u bump upp the voltage on it u can OC it more. same thing applies to ur CPU.

[rourkchris]

I'd just overclock the CPU to reasonable limits temperature permitting and forget overclocking the GPU. Will the 5850 not play everything you play at decent settings? I usually overclock the GPU to benchmark but put it back to stock for everyday gaming.