Topic: AMD Radeon HD 7800 Series Specs Revealed in Leak (Read 8729 times)

I think you know they get special picked chips to make a good impression for the reviewer / public

Legit Reviews and Anandtech were able to reach 1050MHz on the reference 7850 with stock volts (max OC in CCC), and techpowerup got to 1140MHz core on the 7850. If you're not overclocking the ram like these site do, I would guess 1GHz is possible on all but the worst cards. Given it's low power draw, it might be a pretty good card.

7870 cool turbine radiator)

New specs and pictures: http://www.techspot.com/review/504-amd-radeon-7870-7850/

7870: 1280SP 1000MHz clock
7850: 1024SP 860MHz clock

Also new prices: 7870 349$ list price up from 299$

By my calculations, assuming a 7970 can achieve 700MH/s at a very high overclock, (1280/2048) * 700MH/s = ~437 MHs, assuming the 7870 can OC just as high. Divided by 350$, and at best you get 1.25MHs per $, not including tax, plus board partner fees.

The 7970 was supposed to be 549$, but even today the cheapest one I can find is 582$ new. A 7870 with a decent cooler will probably run you 390-400$ after tax. I had very high hopes for these as well, I figured 299$ for the 7870 sounded too good to be true, but I wasn't expecting the shader count to drop as well  

EDIT:
Oops, didn't read far back enough, sorry for the double post 

Thanks for the insight D&T.

Your posts are always pure gold

Which card is best in terms of MHash/$ and density ?

Waiting for 7990 or 7890 ...

Thanks for the updated data.  I updated my stats above.  

The results look more in line with what one would expect now.  On paper, really no standouts over the 7970 other than the 7770.  Even that seems dubious.  6x7770s would only be = ~2x 7970s.  Sure you save a few dollars but unless you plan on having <1.2 GH/s per rig it doesn't make much sense on a density basis.

So IMHO if you want to hash w/ 7000 series your options are:
a) get 7970 seems pretty safe bet at this point
b) wait for 7990.
c) wait to see if any of the smaller cards is an "overclocking champ".

Worthless test, they did the same one with the 7900 series release.

They don't use optimized kernels for GCN, so results for 7000-series are much lower than they should be.

http://www.tomshardware.com/reviews/radeon-hd-7870-review-benchmark,3148-18.html



Although these results seem lower than expected...

It should get much more than that easily.

Mining performance is linearly proportional to clockspeed and shader count among the same architecture, so we can compare it to 7970:

7970 has 2048 shaders, stock clock of 925MHz. It gets about 556MH/s.

7870 has 1280 shaders, stock clock of 1GHz. It should get about (1280/2048)*(1000/925)*556MH/s = 375.7 MH/s. However you can probably clock it to about same numbers as a 7970, so overclocked it could get e.g (1150/1000)*375.7  = 432MH/s. Some can even clock their 7970s to 1.2+ GHz,  so 450+ MH/s might be possible if these clock as good.

Not exceptional, but better than 6900 series, with better power consumption. Although against 5870 it doesn't fare as well, probably has about the same power consumption and hashrate, albeit at higher price.

Edit: Revised numbers slightly upwards, 7970 gets 556MH/s not 550

Someone needs to post BTC numbers.

I doubt it getting more than 230 MHash/s though.

Proove me wrong.

AnandTech Review

http://www.anandtech.com/show/5625/amd-radeon-hd-7870-ghz-edition-radeon-hd-7850-review-rounding-out-southern-islands/1

Looks like some numbers were off.


n.olmos

Very interesting info guys. Didn't see the HD7890 coming though (but I guess it's like AMDs old HD4890 gpus they made a few years ago).That (HD7890) has the same no of shaders as my unlocked HD6950 which makes me question the need to upgrade so soon for me as it's mainly the price and the lack of dual GPUs coming from the HD7xxx at the moment (that will be released later this year).

I wonder how an unlocked HD6950 would compare with an HD7890 since they both have the same no of shaders? I wonder how big the difference would be if they were compared for mining performance (as the no of shadersseems to really affect things).

Good find guys :-)

Hashing performance is very linear relative to shader * clock (when using optimal vectors & workgroup settings to avoid idle shaders).

Nominal theoretical performance (shaders * clock):

Relative theoretical performance (7970 being 100%):

Relative theoretical performance per $ (using list prices):

Still missing complete specs on 7890/7990.

On paper the 7850 looks interesting.     Unless there is a big price drop the 7950 looks to be a dud (and based on the rumored 7890 pricepoint that seems unlikely).  The other cards( 7870, 7750, 7770) seems to be priced properly so there is no reason to pick them over the simplicity of a single high output 7970.

On edit: the updated specs and higher price weakened the 7850s competitive position.  It is now evenly balanced relative to a 7970 (at stock) as are the 7750. 7850 and 7870.  For mining the 7850 seems over priced and the 7770 at least on paper seems a low end bargin.

Of course all that is at stock and if overclocked assuming overclock potential is roughly the same.  If some cards can be pushed harder than others that obviously changes things.

Tom's Hardware > News > Components > Graphics Cards > AMD Radeon HD 7800 Series Specs Revealed in Leak

6:00 AM - February 22, 2012 by Doug Crowthers - source: EXPreview

With the launch of both the HD 7900 and HD 7700 series, AMD is expected to release its HD 7800 series GPUs in March. Today, we get our first peek at the specifications of the HD 7850 and HD 7870.


As reported first of February in a leaked roadmap, AMD is set to release its HD 7800 series graphics cards based on Pitcairn in March. Based on information coming out of Chinese-based EXPreview.com, we may have our first glimpse at the specifications for the new Pitcairn series. The HD 7800 series will utilize AMD's GCN stream processors seen with both HD 7900 and HD 7700 series.

Radeon HD 7850

20 Graphics CoreNext Compute Units
1280 stream processors
80 TMUs
24 ROPs
Memory Bus of 256-bit
Memory size of 1 GB/2GB GDDR5 memory
Clock speeds of 900 MHz core
Memory frequency of 1250 MHz (5.00 GHz effective)
 

Radeon HD 7870

22 Graphics CoreNext Compute Units
1408 stream processors
88 TMUs
24 ROPs
Memory bus of 256-bit
Memory size of 2GB GDDR5 memory
Clock speeds of 950 MHz core
Memory frequency of 1375 MHz (5.50 GHz effective)
 

Early pricing for the HD 7850 has it listed at around $220 dollars and the HD 7870 around $300 dollars. In the second quarter, AMD is expected to release both the HD 7990 and HD 7890. While the specs for HD 7990 are still relatively unknown, the HD 7890 will be based on Tahiti (same as the HD 7900 series). It is expected to feature 24 Graphics CoreNext Compute Units, 1536 stream processors, 96 TMUs, 32 ROPs, and have a 1.5 GB memory with memory interface of 384-bit. Early expectations for pricing has the price of the HD 7890 around $359 dollars.

Please keep in mind, of course, that these specifications are from EXPreview's supposedly reliable source. We won't know for sure until AMD shows its hand. Stay tuned!