AMD Radeon HD 7750 & Radeon HD 7770 GHz Edition Review: Evading The Price/Performance Curve
by Ryan Smith & Ganesh T S on February 15, 2012 12:01 AM EST- Posted in
- GPUs
- AMD
- HTPC
- GCN
- Radeon HD 7000
Compute Performance
Moving on from our look at gaming performance, we have our customary look at compute performance. With GCN AMD significantly overhauled their architecture in order to improve compute performance, as their long-run initiatives rely on GPU compute performance becoming far more important than it is today.
With such a move however AMD has to solve the chicken and the egg problem on their own, in this case by improving compute performance before there are really a large variety of applications ready to take advantage of it. As we’ll see AMD has certainly achieved that goal, but it raises the question of what was the tradeoff for that? We have some evidence that GCN is more efficient than VLIW5 on a per-shader basis even in games, but at the same time we can’t forget that AMD has gone from 800 SPs to 640 SPs in the move from Juniper to Cape Verde, in spite of a full node jump in fabrication technology. In the long run AMD will be better off, but I suspect we’re looking at that tradeoff today with the 7700 series.
Our first compute benchmark comes from Civilization V, which uses DirectCompute to decompress textures on the fly. Civ V includes a sub-benchmark that exclusively tests the speed of their texture decompression algorithm by repeatedly decompressing the textures required for one of the game’s leader scenes. Note that this is a DX11 DirectCompute benchmark.
Theoretically the 5770 has a 5% compute performance advantage over the 7770. In practice the 5770 doesn’t stand a chance. Even the much, much slower 7750 is ahead by 12%, meanwhile the 7770 is in a class of its own, competing with the likes of the 6870. The 7770 series still trails the GTX 560 to some degree, but once again we’re looking at the proof of just how much the GCN architecture has improved AMD’s compute performance.
Our next benchmark is SmallLuxGPU, the GPU ray tracing branch of the open source LuxRender renderer. We’re now using a development build from the version 2.0 branch, and we’ve moved on to a more complex scene that hopefully will provide a greater challenge to our GPUs.
SmallLuxGPU is another good showing for the GCN based 7700 series, with the 7770 once again moving well up the charts. This time it’s between the 6850 and 6870, and well, well ahead of the GTX 560 or any other NVIDIA video cards. Throwing in an overclock pushes things even farther, leading to the XFX BESDD tying the 6870 in this benchmark.
For our next benchmark we’re looking at AESEncryptDecrypt, an OpenCL AES encryption routine that AES encrypts/decrypts an 8K x 8K pixel square image file. The results of this benchmark are the average time to encrypt the image over a number of iterations of the AES cypher.
Under our AESEncryptDecrypt benchmark the 7770 does even better yet, this time taking the #2 spot and only losing to its overclocked self. PCIe 3.0 helps here, but as we’ve seen with the 7900 series there’s no replacement for a good compute architecture.
Finally, our last benchmark is once again looking at compute shader performance, this time through the Fluid simulation sample in the DirectX SDK. This program simulates the motion and interactions of a 16k particle fluid using a compute shader, with a choice of several different algorithms. In this case we’re using an (O)n^2 nearest neighbor method that is optimized by using shared memory to cache data.
It would appear we’ve saved the best for last, as in our fluid simulation benchmark the top three cards are all 7700 series cards. This benchmark strongly favors a well organized cache, leading to the 7700 series blowing past the 6800 series and never looking back. Even NVIDIA’s Fermi based video cards can’t keep up.
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bazinga77 - Wednesday, February 15, 2012 - link
here is the thing to be honest. if you complain about the price that seems like a fair complaint. however one has to wonder how much it costs amd and nvidia in losses to keep dropping prices to stay competitive. at some point it has to catch up with you. with the losses amd has suffered with bulldozer they have to be smarter with the prices. also until nvidia launches something new they can stay a little heavy handed with the prices unless nvidia forces the issue especially as we see some of the older cards go away and amd has said that the 6xxx series cards are no longer in production and haven't been for months. so right now the pricing seems a little bit off but what about once you can't get a 6850,6870, of gtx 460 ti? it will make more sense then.finally if you expected a 77xx series card to blow anything out of the water with its limited memory bandwidth of 128 bit memory then frankly you are either not very intelligent or naive. this is a lower mid ranged card that almost beats last gens upper mid range card. that is not bad. this card was never going to blow the roof off and if you thought it could will that just wasn't the best thought process you ever had.
Markstar - Wednesday, February 15, 2012 - link
I'm sorry, but you entirely missing the point of the whole concept of the IT industry. Graphic cards are not groceries, where you are lucky if you can still buy them for the same price 18 months later. The desktop market is declining, so there are plenty of computers out there fast enough to run Firefox and Word.There HAS to be an incentive to buy new parts - and especially now that integrated graphics are fast enough for 1080p and casual games, this HAS to involve a performance gain in some form or another to get people to buy a dedicated graphic card, let alone upgrade from their existing one.
Who is going to buy this card? Seriously, who? A person who is tight on money should look on Ebay, where you get a used 5770/6770 for $60. Everyone else is bettor off buying the 6850 or going to NVidia.
Frankly, you are a bit naive if you think we will applaud AMD for releasing such an underachiever. As it stand now, AMD would have been better off with another round of rebadging (thereby saving money on R&D and freeing up 28nm wavers).
Sad, very sad. :(
bazinga77 - Wednesday, February 15, 2012 - link
integrated graphics aren't good enough to run most games. if by casual games you mean angry birds then i guess i would agree with that.most gpu's come out higher in price initially then we expect or want especially when newer cards come out while the other vendor, in this case nvidia, is a ways away from releasing there next gen cards. sure we can bash this card but to do so we have to assume nvidia is going to blow amd out of the water. sure amd has been rebranding their cards the last two cycles but nvidia is more guilty of that then anyone. so as the current market stands the price is a little high. but lets be honest it is only looking that way because cards like the 6850 are still available, which won't be the case in the very near future.
i guess if you want to buy a used gpu off of ebay with no warranty then someone can do that and if it craps out in a month then they can deal with that as well. and if someone is tight on money and only going to spend $60 then i doubt they are on a site like this and care about benchmarks let alone at 1080p etc.
the gtx 460 is becoming harder and harder to find and the gtx 560 is over $200 so i don't see a huge issue. i expect the cards to lower in price next month when the 7850 launches and the 7770 will settle down into a more comfortable range. if you buy a gpu or cpu day one you will always pay more typically then a couple of months later.
i don't think amd should be applauded but i think people need to be realistic. when nvidia released the 550 ti it didn't even get close to the gtx 460 ti, yet that is the exact thing amd is getting bashed for. the 550 ti competes with the 6770 and 6790, while the 6850 was trying to get closer to competing with the gtx 560 and gtx 460. like i said the 550 ti didn't perform better than the gtx 460, not even close, yet you expect amd to release a card that would typically compete against a card like the 550 ti (in its respected generation, being the next nvidia card that would replace the 550 ti) and you expect it to compete at a higher class than it is released. sure the price isn't perfect but you are expecting a civic released to compete with a corolla to actually compete with bmw 1 series.
bhima - Wednesday, February 15, 2012 - link
Uhh... its really not hard to find a GTX560 for under $200.$170 : http://www.newegg.com/Product/Product.aspx?Item=N8...
$175: http://www.newegg.com/Product/Product.aspx?Item=N8...
$185: http://www.newegg.com/Product/Product.aspx?Item=N8...
We expect the card to compete with this because its priced a bit higher than this old tech:
HIS ICEQ 6870 $170: http://www.newegg.com/Product/Product.aspx?Item=N8...
chizow - Wednesday, February 15, 2012 - link
Great points Markstar, I'm glad there's others who understand the issus with the 7-series pricing many people have.TerdFerguson - Wednesday, February 15, 2012 - link
Thanks for the honest review. AMD deserves to be dragged through the coals for trying to sell us something that costs more and performs worse than a two-year-old card. This constitutes an epic failure in the world of consumer electronics. The more you stress it, the more it feels like you're an advocate of the consumer and not the greedy corporate suits.Bull Dog - Wednesday, February 15, 2012 - link
On VCE and the Test page, "7700 series launch is a bit more unsettling. These are cards that are going to be paired with slower GPUs, where having a high speed H.264 encoder is going to be all the more important."I believe it should be CPU and not GPU there.
pandemonium - Wednesday, February 15, 2012 - link
I think it's pretty obvious that AMD is milking what they can while the buzz of the architecture and die size is fresh - primary opponent being absent in their next series release and all. In a month it'll be a different story. Prices will have settled in to where they belong after all the manufacturer's have their versions readily available. I don't really see how this is a big deal. Has any card released been placed appropriately immediately at debut?kevith - Wednesday, February 15, 2012 - link
I am the lucky owner of a XFX HD4770.It´s fairly ok for my use, music production and occasional gaming.
I would like something a bit newer though, that can handle new games in full HD.
And now I have witnessed the launch of 5750/70, 6750/70 and now 7750/70. The 5770 being "the peoples champ" for quite a while, as my 4770 could and would have been in its time, if it wasn´t for availability problems. (Probably created by AMD on purpose, realizing, that the card was to cheap.)
But as far as I can read everywhere, the 6770 is simply another 5770. And the 5770 wouldn´t really give me a significant improvement over my 4770. Never mind DX11 and Eyefinity and all that jazz.
SO. Where should I go for a difference I can feel and see right away? 6870? Prices doesn´t give ANY clue anymore, as Anandtech pointed out with this - and previous articles.
I look at Tom´s "Best card for the money..." round-ups, but I don´t get much wiser.
It sure is a jungle out there...
silverblue - Wednesday, February 15, 2012 - link
The 4770 was far too similar in performance to the 4830 it was replacing. The 4770 was more of a test for 40nm manufacturing than anything else.The 6850 and 6870 are definitely worthy of the cash.