Bitcoin Forum

Bitcoin => Mining => Topic started by: pandemic on May 31, 2011, 11:37:25 PM



Title: radeon 5850 > 6870, why?
Post by: pandemic on May 31, 2011, 11:37:25 PM
The research I've done (just a bit) says the 6870 is better than the 5850 but it seems like the opposite is true for mining. Why is that?


Title: Re: radeon 5850 > 6870, why?
Post by: JJG on May 31, 2011, 11:44:43 PM
The research I've done (just a bit) says the 6870 is better than the 5850 but it seems like the opposite is true for mining. Why is that?

Need [much] more info.

What's your research?

What was your testing?

Clocks? SDK? Program? Kernel?

What's 'better'? Pure speed or power efficiency?

Share your numbers.


Title: Re: radeon 5850 > 6870, why?
Post by: russelljohnson on June 01, 2011, 01:20:21 AM
My 5850 mines at 360MH/s, paid $135
My 5870 mines at 420MH/s, paid $100
My 6970 mines at 370MH/s, paid $300

Go figure.


Title: Re: radeon 5850 > 6870, why?
Post by: mrenouf on June 01, 2011, 01:30:55 AM
A 5870 for $100 ?!? WTH?? ???

Either I just got SERIOUSLY ripped off or the market supply/demand has driven the prices way up since then.


Title: Re: radeon 5850 > 6870, why?
Post by: russelljohnson on June 01, 2011, 02:08:27 AM
A 5870 for $100 ?!? WTH?? ???

Either I just got SERIOUSLY ripped off or the market supply/demand has driven the prices way up since then.

Naw... I bought a refurbished 4870x2 for $100 and it was defective. Manufacturer replaced it with a 5870. I'm a happy camper


Title: Re: radeon 5850 > 6870, why?
Post by: mrenouf on June 01, 2011, 02:19:48 AM
So. Releived.  :P


Title: Re: radeon 5850 > 6870, why?
Post by: IlbiStarz on June 01, 2011, 02:31:00 AM
At stock I think they both mine at about the same rate, but all core mhz increases after that lean in the 5850's favor due to having more stream processors. Plus it's cheaper as well :D


Title: Re: radeon 5850 > 6870, why?
Post by: russelljohnson on June 01, 2011, 03:26:36 AM
The 6 series uses significantly more electricity while performing worse. Why?


Title: Re: radeon 5850 > 6870, why?
Post by: compro01 on June 01, 2011, 04:28:31 AM
the 6870 is optimized a bit differently.  it gives better graphics performance, but doesn't do GPGPU work as well.


Title: Re: radeon 5850 > 6870, why?
Post by: bcpokey on June 01, 2011, 09:15:33 AM
The 6 series actually does not use "significantly more electricity".  In fact a 6870 uses less electricity than a 5850, so... yeah. The 69xx series is a bit more power hungry due to additional tesselation units, rasterizers, higher clocked mem profiles etc, all things that don't help mining at all, and doesn't match up against the 5870 due to the 5870s ridiculous number of stream processors. The 5870 is just a beastly card though, which is why it is the golden miners card, and is not really a fair comparison.

The 6 series has a reduced number of stream processors that are clocked higher and a slightly improved engine. This makes it more power and temp efficient, it scales better in crossfire and does better at tesselation, all great qualities for gamers. For miners the improvements provide essentially nothing, and so you get a slightly more power efficient card that typically overclocks much more poorly for mining.

It has the advantage of being actually available for purchase however.


Title: Re: radeon 5850 > 6870, why?
Post by: Betsinski on June 01, 2011, 09:27:54 AM
How about 5830 compared to 5850 for mining ? Which do you think is better ?


Title: Re: radeon 5850 > 6870, why?
Post by: gat3way on June 01, 2011, 10:44:26 AM
6870 is slightly slower than 5850 in fact, the difference is not huge though.


Title: Re: radeon 5850 > 6870, why?
Post by: Aqualung on June 01, 2011, 11:21:05 AM
How about 5830 compared to 5850 for mining ? Which do you think is better ?
they are very close in Mhash/$, but if you have enogh money 5850 is better, because it will give you more coins in the future


Title: Re: radeon 5850 > 6870, why?
Post by: airdata on June 01, 2011, 02:41:44 PM
6870 is slightly slower than 5850 in fact, the difference is not huge though.

Yep. I got an xfx model of each for roughly the same price. The 5850 was a little cheaper.  The 5850 gets 290MH and the 6870 gets 260-270MH


Title: Re: radeon 5850 > 6870, why?
Post by: pandemic on June 02, 2011, 01:30:15 AM
What does the 5870 get? I'll have to start looking for those cards.

Funny thing is tigerdirect.ca has the 5850 for sale for about $250 a piece and the 6870 for about $220. I'm also looking at both visiontek for the lifetime warranty. I was just curious why the "better" GPU was $30 less :P