AMD Radeon 7 Series

[edplayer]

hi guys. Saw the other thread was locked so starting a new one.

So we have seen some reviews of the 7970.

Can we get some speculation on the estimated performance of the rest of the (GCN) lineup? I see that a 7950 is about 7/8 of a 7970 with the same rops and slightly less memory bandwidth. Would that be about GTX 580 level of performance?

How about the Pitcairn XT and Pro? How would they compare to current AMD and Nvidia cards?



Please think before you post. The previous thread was closed for good reason:

This thread has turned into little more than a red vs. green trollfest, as evidenced by repeated characterizations of non-conforming opinions as being indicative of "teams" and "fanboys".

Too much trollage to waste the volumes of moderator time necessary to cleanup and infract. Instead I am just going to lock this thread.

Start a new one. Expect persistent moderator presence and strict enforcement of the rules. The trolling, baiting, flaming, and inflammatory posting needs to stop.

Administrator Idontcare

 

[MrK6]

Isn't the 7950 the only other GCN part and the rest VLIW4? Or did I miss something? I'd say the 7950 will probably be ~GTX 580, but obviously consume less power and go for $450. I still see them having to drop it to ~$400, especially if it won't unlock.

 

[edplayer]

That is what I read a while back but recently I have been seeing other opinions. That 7600 series and lower will be based on VLIW5 and everything above would be GCN.

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[vailr]

I'd be interested in some of the "bargain basement" 28nm (77xx) series Radeon video cards.
When might those start appearing on Newegg/Amazon/etc.?
Preferably with a cooling fan such as used on the MSI Cyclone series of Radeon cards.

 

[VulgarDisplay]

The things I see coming from AMD below the 7950 don't appear that impressive on paper. I don't see them offering 20-40% more performance than comparable parts for the same price brackets we are seeing now.

That's where I get discouraged by the 7970's price/performance. AMD is fully justified selling it where they are, but any theorizing I do about 7870/7850 performance leaves me feeling that they won't be faster than 6950/6970. I'm guessing AMD is going for 15% or so less performance each step down in their lineup.

 

[edplayer]

well that chart claims the 12th of February. I saw something on fudzilla saying availability of the 7970 will be good on the 9th so maybe it will be the same for Pitcairn. I'm thinking it might be a month or more later though for custom cooler models but we'll see

 

[edplayer]

The things I see coming from AMD below the 7950 don't appear that impressive on paper. I don't see them offering 20-40% more performance than comparable parts for the same price brackets we are seeing now.

Yeah, I kind of get that same feeling. I'm waiting for Russian to post his opinion on them.

 

[Vesku]

7890 looks like it will be similar to 6970 but probably able to OC higher?

 

[bunnyfubbles]

I think the real kicker will be how well the Pitcairn 7800s perform (the 7890 Tahiti is a bit misleading, should really be a 7930), it would have been extremely interesting to see if they would have been die shrunk 6900s but they seem too cut down to be too noteworthy.

Granted, I'm sure they had to cut them down enough as a 6900 @ 1200+MHz with some overclocking would certainly start infringing on 7900 level game performance but at nearly half the cost.

 

[Vesku]

Some people are saying 7800 series is GCN and if so should offer more tessellation performance than the 6900 design.

 

[Lonbjerg]

Some people are saying 7800 series is GCN and if so should offer more tessellation performance than the 6900 design.

AMD dosn't do tesselation in it's shadercores the same way NVIDIA does, they just beefed up their geomety units...something they could have done for VLIW4/5 too, so the shader architechture(GNC/VLIW4/VLIW5) is irrelevant for AMD's tessellation performance.

 

[Vesku]

GCN implies the beefed up tesselation though, as I doubt they would retrofit 6900 series die shrink with it.

 

[Lonbjerg]

GCN implies the beefed up tesselation though, as I doubt they would retrofit 6900 series die shrink with it.

They choose to do it that way.
you can see it when the 28nm VLIW4 low end cards comes out, if they got the updated geomety engines.

GNC refeers to the shadercores, plain and simple:
http://www.anandtech.com/show/5261/amd-radeon-hd-7970-review/2

Notice how the tesselation unit are decoupled from the shadercores in both VLIW4 and GNC:

WLIV4

GNC:

It saves a lot of confusion on these boards when people don't confuse stuff.

GNC, VLIW4, VLIW5, CUDA Cores = shader cores.
Tesselator(AMD), Geometry Engine(AMD) = Fixed function tessellation units.
PolyMorph Engine(NVIDIA) = shader based tessellation.

What that mean is that for NVIDIA their shadercores matters directly as they do the tessellation computation.
For AMD their shader cores don't matter in tessellation, as they don't do tesselation.

And like I stated before, they(AMD) can exchange their fixed tessellation units on VLIW4 to match the tessellation of the new cards.

But it has nothing to do with the GNC architechture...GNC is about going more GPGPU than VLIW4.

TL;DR:

For AMD shaders has nothing to do with tessellation, for NVDIA the opposite is true, unlike your statement.

 

[Vesku]

I wasn't trying to make that detailed of a distinction. Just saying the rumors point to a scaled down GCN for 7800 series instead of 6900+ arch. GCN would mean the improved tesselators come with.

Thank you for the basic arch primer, gives some insight into what AMD can and has prioritized.

 

[Silverforce11]

There was rumors of 7950 with less ROPs, made me worried it will perform poorly and never be able to "catch up" with an OC, but seeing as its got identical ROPs, for around $400 and getting >gtx580 performance at ~160W is excellent. Add their hefty OC headroom and you have a winning product.

 

[VulgarDisplay]

There was rumors of 7950 with less ROPs, made me worried it will perform poorly and never be able to "catch up" with an OC, but seeing as its got identical ROPs, for around $400 and getting >gtx580 performance at ~160W is excellent. Add their hefty OC headroom and you have a winning product.

No one has benchmarked one yet, so we'll just have to wait and see if it does perform better than a GTX580.

 

[flopper]

20-25% less than a 7970 for the 7950.
there be 3gb and 1.5gb versions.
Matching or slightly beat the 580.

 

[Grooveriding]

If the 7950's having 7/8 the physical hardware of the 7970 has an equal translation to FPS performance, it will be about 10% faster than a GTX 580 averaged out over all resolutions.

If it plays out that way 7950 will be 10% faster than a 580 at 1080/1200P and 13% faster at 1600P.


78XX will also be GCN and there are rumours that 77XX will too be using GCN. So a true replacement will come for the 5770/6770.

http://lenzfire.com/2011/12/gcn-architecure-from-amd-radeon-hd-7700-to-hd-7900-series-cards-68336/

Sounds right to me, rebranding the 6770 to 7770 would be plain ignorant. That card is too long in the tooth to carry over a third time.

 

[Arkadrel]

if... 7970 = ~25-30% faster than 580 then:

7950 @ (1792/2048)x100% (~87% of a 7970) = ~114% of a 580.
7890 @ (1536/2048)x100% (~75% of a 7970) = ~98% of a 580.


I think the 7890 is the card that matches the 580.
Also that the 7950 will have like 10-15% ontop of a 580.

This is without factoring in any improvements from now until release date, with drivers.... maybe that fetches like ~5% performance or something by then, and you ll have these cards looking abit better.

And/or without factoring in any custum designs with factory overclocks.

 

[maddie]

No one has benchmarked one yet, so we'll just have to wait and see if it does perform better than a GTX580.

If the quoted specs are accurate, the 1.5 gig 7850 would pretty much equal a 580GTX (at least), based on the 7970 reviews. Should be THE card to get.

 

[nsavop]

It looks like AMD is well prepared with ample stock of 7970's this time around, good news for those in the market on Jan 9.

http://www.maximum-tech.net/amd-is-ready-with-huge-stocks-of-radeon-hd-7970-7759/

 

[Lonyo]

I'm surprised there are no reviews or proper news of the HD7950 if it's supposed to be released also on the 9th. It's also the card that would force NV to change prices, assuming it's equal or better than the GTX580 in performance.

 

[ArchAngel777]

Why do I have this urge to buy one of these? It wouldn't be much of an upgrade over my current setup... I hate the upgrade fever.

 

[Arkadrel]

@ArchAngel777

Yeah 460 SLI is like ~10% away from a 580 in performance, your basically just about as fast as a 6970.

At most a stock 7970 would be like 40% or so for you... kinda like if you had a 6970. If you overclocked the hell out of it (compaired to stock 460 SLI) the most performance differnce would be like ~55-60% gain.

Maybe you dont like SLI? or feel mircostuttering?
That said, 460 SLI is pretty sweet on its own, and even having 6970 ish performance, with the current games on the market is more than enough (unless you game at like 2560x resolutions).

 

[SirPauly]

How about the Pitcairn XT and Pro? How would they compare to current AMD and Nvidia cards?

Those are my interest as well based on these are more aimed at the Sweet Spot.