GPU Overclock Questions.

[KJamesJR]

Hi, I had a few questions about GPU overclocking...

I currently have the latest HIS HD 5770 model. Through AMD Overdrive it's been O.C.'d to: 910MHz and 1,300MHz memory clock. It's currently running stable at 32c and 30% fan speeds... Under full load it can get up to 50c and continue running stable at these setting.

So I was looking at some HD 6850's... Some of these core clocks are only 775MHz & 1000MHz memory clock. Still only 1GB of memory.

Does this mean my current GPU is out preforming these stock GPU's? Is it worth taking a step up? I am interested in the 6850's also the 6870's. Though I'm looking to spend around $150USD after rebate's etc... Any suggestions?

Some cards I'm interested in:

Newegg.com - XFX HD-687A-ZHFC Radeon HD 6870 1GB 256-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card

Newegg.com - HIS H687FN1GD Radeon HD 6870 1GB 256-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card

Newegg.com - XFX HD-685X-ZCFC Radeon HD 6850 1GB 256-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card

Newegg.com - SAPPHIRE 100315L Radeon HD 6850 1GB 256-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card with Eyefinity

 

[Sean W.]

watch this, it will answer all your questions...

Video Card Shopping Tips: Why Memory and Clock Speeds Don't Matter NCIX Tech Tips - YouTube

 

[KJamesJR]

Okay if I heard him right, memory really isn't an issue unless I'm running very large formats, which I'm not. So I'm set on 1GB. I guess that leaves the core clock and streaming processing units?

Core clock on the 5770 is 850, mine is at 910, 6870 is at 900. The streaming processing units are at 800 on the 5770, which is 250 less than the 6870 (does that really make a huge difference?).

I'm sure the stock core clock on the 6870 can be taken up a bit, though is it really enough to brag about? Are there factors I'm missing here?

 

[patonb]

The cores/processing units are what actually does the work, so more = better.

Plus the cpus have been redesigned so they run so much better too..

 

[Sean W.]

compare benchmakrs to a 5770 and 6850... i can tell you right now, a stock 6850 is at least twice as fast as your overclocked 5770