Overclocking a HD 5770!

Sal Paradise · *Last edited by Sal Paradise; 07-20-2010 at 16:15.*

I've recently bought a Sapphire HD 5770, and I've started overclocking it using Catalyst Control Center.

The stock speeds are:

Clock speed - 850Mhz

Memory speed - 1200Mhz

So far I've been able to get the following speeds using the auto-detect feature:

Clock speed - 950Mhz

Memory speed - 1235Mhz

Do you think there is much headroom left for overclocking? My specs are listed on the left-hand side. I have no cooling system other than the stock, and I have not attempted to overclock my processor.

Any help would really appreciated!

Edit: Currently my GPU is running at 40c at idle, if that helps.

Sal Paradise · *Last edited by Sal Paradise; 07-20-2010 at 16:40.*

Another question - and this may sound a little "noobish" - But if you manually change the GPU fan speed, does the fan always stay at that speed regardless of how much load it is under, or does it change in order to keep the GPU at a safe temperature? I manually changed the fan speed from 35% to 40%.

ScoobyDooby · 07-20-2010, 18:26 | posts: 5,260 | Location: BC, Canada

when you manually change the fan speed it will stay at whatever speed you've specified, so be sure to place the speed high enough to provide enough cooling.
Otherwise, your clock speeds seem fine and idle temps at 40 are very good.. the real test comes when the cards are taxed.. you may have plenty more headroom but you wouldnt know unless you tried to push it farther. if you did you would probably do well to use software to up the voltages a bit. This would definitely help you to reach higher clocks.

Sal Paradise · 07-20-2010, 19:26 | posts: 64 | Location: Northern Ireland

Quote:

Originally Posted by ScoobyDooby

when you manually change the fan speed it will stay at whatever speed you've specified, so be sure to place the speed high enough to provide enough cooling.
Otherwise, your clock speeds seem fine and idle temps at 40 are very good.. the real test comes when the cards are taxed.. you may have plenty more headroom but you wouldnt know unless you tried to push it farther. if you did you would probably do well to use software to up the voltages a bit. This would definitely help you to reach higher clocks.

Regarding the fan speed, I took it off manual control. Does this mean that the GPU will manage the fan itself? Once I switched manual off the fan speed rolled back to 35%.

Can you recommend a program that will allow me to test overclocks at high loads?

Lasikie · 07-20-2010, 20:04 | posts: 18 | Location: St Helens

Quote:

Originally Posted by Sal Paradise

Regarding the fan speed, I took it off manual control. Does this mean that the GPU will manage the fan itself? Once I switched manual off the fan speed rolled back to 35%.

Can you recommend a program that will allow me to test overclocks at high loads?

Msi Afterburner and Kombuster I think.

Mufflore · 07-20-2010, 20:41 | posts: 9,519 | Location: UK

The auto detect feature hasnt been very successful at finding stable overclocks for me.
Test stability further than just using the overclocking tool.

Idle temps dont tell you much as the card isnt pushing any extremes at idle.

Sal Paradise · 07-20-2010, 21:16 | posts: 64 | Location: Northern Ireland

Has anyone ever had problems with CCC auto-tune before? Is the overclock likely to be unstable. So far I've been playing games like Napoleon: Total War at Ultra settings for a couple of hours and with no problems. Is this reassuring, or am I not stressing the GPU enough. As soon as I leave the game, I check the GPU temperature and it's usually around 50c or 52c.

Mufflore · 07-20-2010, 21:38 | posts: 9,519 | Location: UK

Try Crysis!

52C is hardly pushing the card.

Yadda · 07-20-2010, 23:58 | posts: 58 | Location: UK

Like someone's already mentioned, I'd recommend downloading MSI Afterburner. It will allow you full overclocking control, as well as the ability to configure and save your own fan speed profile. It also gives you really good monitoring graphs too for GPU temp, fan speed etc. It's the best app for the job.

Regarding overclocking, I think most 5770's get to around 950MHz GPU on standard volts. To go much further you'll need to increase the GPU voltage. Afterburner allows this adjustment but some card's BIOS' limits this. I'm not sure of the exact implications and solution as my cards are Asus "voltage tweak" 5770's so don't have this limitation. Anyway, 1GHz GPU is easily achievable on both my cards at 1.225v-1.250v.

Regarding memory, you should be able to run at least 1275 (5100), maybe more, especially if you have a V1 card with Hynix chips (instead of the later cards which used Samsung). The thing with overclocking memory on these cards is that unlike previous generations of graphics card, these will not artifact when the memory is pushed too far. They throttle instead. So the only way to know you've gone too far with the memory overclock is to benchmark. Once the performance starts dropping, you know you've gone too far.

Long post. Apologies, I rambled.

Sal Paradise · 07-21-2010, 21:16 | posts: 64 | Location: Northern Ireland

Quote:

Originally Posted by Yadda

Like someone's already mentioned, I'd recommend downloading MSI Afterburner. It will allow you full overclocking control, as well as the ability to configure and save your own fan speed profile. It also gives you really good monitoring graphs too for GPU temp, fan speed etc. It's the best app for the job.

Regarding overclocking, I think most 5770's get to around 950MHz GPU on standard volts. To go much further you'll need to increase the GPU voltage. Afterburner allows this adjustment but some card's BIOS' limits this. I'm not sure of the exact implications and solution as my cards are Asus "voltage tweak" 5770's so don't have this limitation. Anyway, 1GHz GPU is easily achievable on both my cards at 1.225v-1.250v.

Regarding memory, you should be able to run at least 1275 (5100), maybe more, especially if you have a V1 card with Hynix chips (instead of the later cards which used Samsung). The thing with overclocking memory on these cards is that unlike previous generations of graphics card, these will not artifact when the memory is pushed too far. They throttle instead. So the only way to know you've gone too far with the memory overclock is to benchmark. Once the performance starts dropping, you know you've gone too far.

Long post. Apologies, I rambled.

Ran Kombustor with the settings I listed for ten minutes.

At 100% load the temps hovered around 59c and 60c.

Is this good? I've heard that 75c is the threshold for safe GPU temps.

ScoobyDooby · 07-21-2010, 03:16 | posts: 5,260 | Location: BC, Canada

thanks for the info though Yadda.. i will be xfiring 5770s in a little while here and ocing both cards so its good to know that about the memory.

Mufflore · 07-21-2010, 21:48 | posts: 9,519 | Location: UK

Temps are great, it looks like you have a good card.