The Lowest heat producing Radeon card?

[420]

Which card produces the least heat per hash

I want to buy it

[Littleshop]

Which card produces the least heat? (and hashes efficiently)

I want to buy it

The least heat per hash would be a 7970.  You do need to find one that has unlocked voltage though, that can make a big difference with undervolting.

[ssateneth]

The least heat (period) would be a radeon 5450 or 6450.

[zvs]

7790's should get around 300mhash @ max of 85 watts (ed: hmm, probably thinking of the 7770 and like 100 watts?  maybe 150 for the 7790?)?  what is the 7970?  

[crazyates]

The lowest heat producing card will either mean A) the smallest, cheapest, slowest card you can find, or B) a high end card that's undervolted to all hell.

For the former, you're talking about a 5450 (19MH/s @ 19W TDP), or a 7750 (150Mh/s @ 55W TDP). Both of those also have the advantage of being powered right off the PCIe slot, so you don't need to upgrade your PSU to use them.

For the latter, you can't get much better than a 7970. I got mine down to 380MH/s @ 61W. Those voltage unlocked cards can reach some awesome efficiency numbers. Not the most profitable, but the most energy efficient GPU out there.

[420]

obviously i mean the least heat per hash

[abbeytim]

basically you want best mh/watt    cause watts gets transferred into  heat

[GenTarkin]

I would second the 7790 - Ive gotten one to do 315mh/s @ 1200mhz
The thing had hardly any hot air around the HSF and it was running at like 50-60C
Used barely any power, it was over 3mh/s/watt