HD 6770

[crazyates]

In general, you should underclock your GPU RAM when mining BTC, and overclock your GPU RAM when mining LTC.

I know Litecoin uses Scrypt and it's a different ballgame, so could anyone explain why it's performing so much better for LTC mining? And would over-clocking the card's memory speed it up for Litecoin?

Also... Is it safe to tweak clock settings while your GPU is mining?

As for Nvidia vs ATI, see this article: https://en.bitcoin.it/wiki/Why_a_GPU_mines_faster_than_a_CPU#Why_are_AMD_GPUs_faster_than_Nvidia_GPUs.3F

As for changing clocks while the card is in use: in general, yes, it's fine. Actually, CGMiner does this automatically, by changing your clocks on the fly with dynamic overclocking to prevent overheating (if you set it up). I have had some issues with MSI AB and unofficial overclocking locking a card into low power mode when you change a setting while mining, requiring a reboot.

[1715373861]

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[1715373861]

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[Gatorhex]

Some cards are OEM models and will only run half speed (or not at all) with AMD drivers. You need to use the driver from you card manufacturer.

Just got "OEM brown box" 7850 crossfire for Christmas and I was like WTF they run slower than my old 5830s!

After a while I figured out they were running 430/600 instead of 860/1200 and it was only fixed with the manufacturers driver disc.

The 6770 is not a good card, had one, it runs hot and dies if you get a hot summer. It too is an OEM card!  

[crazyates]

Some cards are OEM models and will only run half speed with AMD drivers. You need to use the driver from you card manufacturer.

Just got 7850 crossfire for Christmas and I was like WTF they run slower than my old 5830s!

After a while I figured out the were running 430/600 instead of 860/1200 and it was only fixed with the manufacturers driver disc.

What?! I'm not saying I'm the know-all source for GPU drivers, but I've never heard of anything like that.

[KWH]

When the GPU is seen as idle in the OS, it underclocks. I usually see half the core and memory speeds.

[Gatorhex]

Some cards are OEM models and will only run half speed (or not at all) with AMD drivers. You need to use the driver from you card manufacturer.

Just got "OEM brown box" 7850 crossfire for Christmas and I was like WTF they run slower than my old 5830s!

After a while I figured out they were running 430/600 instead of 860/1200 and it was only fixed with the manufacturers driver disc.

The 6770 is not a good card, had one, it runs hot and dies if you get a hot summer. It too is an OEM card!

What?! I'm not saying I'm the know-all source for GPU drivers, but I've never heard of anything like that.

The 6770 was intended as an OEM ONLY RELEASE but XFX fecked up and boxed it for retail.

"6770 will not install"
>"From what I understand the 6770 is only supposed to ship to OEM's for use in Pre-builts, how did you get one from Best Buy?"
>>"Just to give everyone a heads up. I just spoke to AMD and they are not supporting the 6770 card for retail. Mark stated they have talked about releasing it to retail but have not made this step as of yet. He also checked all driver files to see if they had a driver for the 6770 and the 6750. He stated they do not have any support for these. He also checked the beta 11.4 and there is no plans to have a 6770 driver on there either."
>>>"Having just purchased this card and successfully installed it, I can say that there are drivers on the disc. One would assume the latest drivers straight from AMD would support this card, however that was not the case. I had to rollback my drivers to those from XFX's site to get the card working after I updated with AMD's most recent release."
http://www.tomshardware.co.uk/forum/314448-15-6770-install

[KWH]

IIRC the 6770 is basically a rebadged 5770 with some minor updates. They normally run quite cool.

[Gatorhex]

IIRC the 6770 is basically a rebadged 5770 with some minor updates. They normally run quite cool.

My 6770 was running about 76c at stock. This was okay back when we were allowed to use lead in solder! But a really hot summer killed it on that damn EU lead free solder that was also killing early XBOX 360s and PS3s with "ring of death".

My 5830's ran at 60c, and my 7850's run at 50c!

Really the 6770 sells for the same price as a 5830 and that's a much faster, cooler, quieter card with no OEM driver issues.

Video of a 5830 running Battlefield 3 in 1080p Ultra 0xAA with FPS and Temp counters.
http://www.youtube.com/watch?v=EjCOwK3VJDc

[KWH]

The 5770's that I have had were stock cooling and running Boinc wide open and overclocked yet they stayed under 70c. (alt fan profile was used)
I believe they will withstand 100-104c before disaster strikes, just not sure how long one would last at that level. Cramped case or poor cooling perhaps? Lead free solder is crap IMO.

[Cranky4u]

My testing rig runs 2 * 6770 for BTC & LTC mining in Australia.

The cards have been flogged for nealry 18 months now with card temps in the mid 80s celsius for a smooth 205MHs / 200KHs (BTC/LTC).

I have used cross-fire but then the slave cards only run at ~90% however, if crossfire is removed, they runn ~99%

I found cgminer was essential to smooth running.

Overall, they are very sturdy cards for Australian conditions.

[creativex]

6770s are the coolest running cards I own. They aren't powerhouses, but they are power efficient and reliable.

[debianlinux]

I'm running 5770's specifically because they play nicely with the 300W PSUs in the spare machines I had to plug them into.