ATI’s Radeon HD 5770 And 5750
There’s really no need to rehash all of the architectural elements that comprise the Radeon HD 5770 and 5750—if you want to know more about how ATI improved this generation’s architecture over RV770, check out our original Radeon HD 5870 review. When I say that the Radeon HD 5770 is half of that flagship, I’m being literal.
As mentioned, the Juniper GPU consists of 1.04 billion transistors (to Cypress’ 2.15 billion). It sports 800 ALUs (to Cypress’ 1,600). It leverages 40 texture units (to Cypress’ 80). It boasts 16 ROPs (to Cypress’ 32). I think you get the picture here. If not, a die block diagram comparison should do the trick:
Even the speeds and feeds work out comparatively. Radeon HD 5870 employs 1GB of GDDR5 memory running at 1,200 MHz, delivering 153.6 GB/s. The Radeon HD 5770 also sports 1GB of GDDR5 at 1,200 MHz, serving up 76.8 GB/s. Eight hundred “shader processors” times 850 MHz times two gives the Radeon HD 5770 1.36 TFLOPS of compute power, versus the 5870’s 1,600 * 850 MHz * 2 = 2.72 TFLOPS.
| Radeon HD 5770 | Radeon HD 5750 | Radeon HD 4870 | |
|---|---|---|---|
| Compute Performance | 1.36 TFLOPS | 1.008 TFLOPS | 1.2 TFLOPS |
| Transistors | 1.04 billion | 1.04 billion | .956 billion |
| Memory Bandwidth | 76.8 GB/s | 73.6 GB/s | 115 GB/s |
| AA Resolve | 64 | 64 | 64 |
| Z/Stencil | 64 | 64 | 64 |
| Texture Units | 40 | 36 | 40 |
| Shader (ALUs) | 800 | 720 | 800 |
| Idle Board Power | 18W | 16W | 90W |
| Active Board Power | 108W | 86W | 160W |
Thus, all of the same architectural balancing that went into the Radeon HD 5870 should carry over here, and we should see a performance picture as good or better than what ATI’s Radeon HD 4870 was able to do, given its 800 shader processors at 750 MHz (totaling 1.2 TFLOPS)and GDDR5 memory running at 900 MHz.
Oh, but there’s a rub. The Radeon HD 4870 also employed a 256-bit bus, giving it 115.2 GB/s of memory bandwidth. We’ll have to see how that notably different specification affects the overall performance picture.
The Radeon HD 5750 centers on the same Juniper GPU as its big brother. ATI disables one of the chip’s 10 SIMD cores, switching off 80 ALUs and four texture units. The processor’s core clock is then decelerated to 700 MHz, yielding a nice round 1 TFLOPS of compute muscle. ATI doesn’t mess with the GPU’s back-end, so you still get 16 ROPs and a 128-bit memory bus loaded with 1GB of GDDR5 memory. However, the clocks there are slightly lower too, yielding 73.6 GB/s from the 1,150 MHz RAM.
The Boards
The Radeon HD 5770 itself is shorter than the Radeon HD 5850, which was already shorter than the behemoth Radeon HD 5870. At 8.5” (an inch shorter than the 5850), it’s a very case-friendly card.
As with the larger Cypress card, the 5770 employs rear-mounted auxiliary power, though it only needs one connector instead of two. Further, ATI recesses the plug a bit, so protruding cables are less likely to get in the way.
We were already blown away by ATI’s efforts to minimize power consumption with the Radeon HD 5870 and 5850. However, the smaller Juniper die is even more miserly. At idle, the Radeon HD 5770 is rated at just 18W (down from the 5850’s 27W and the 4870’s ravenous 90W). Under load, the Radeon HD 5770 uses just 108W (versus the 5850’s 151W). Already you can see how this might be the world’s most perfect HTPC card. But wait…there’s more.
ATI’s Radeon HD 5850 sports an entirely different design. Up until now, all of the 5000-series cards have featured enclosed shrouds with blower-type coolers that exhaust air from a vent on each card’s I/O bracket. The Radeon HD 5750 sports a simpler dual-slot heatsink/fan combination. The PCB is shorter still at 7.25,” and it likewise comes equipped with a single auxiliary power connector.
This could be an even better solution for big-screen gamers and theater enthusiasts. Lower clocks and a simpler cooling implementation mean a slightly more conservative 16W idle footprint, and a load requirement of up to 86W. As we’ll see in the benchmarks, this is no speed demon (at the risk of ruining several pages worth of data, it’s a bit quicker than a Radeon HD 4770); however, you’ll find that’s often enough to play at 1920x1080. And the addition of Eyefinity/bitstreaming really makes the 5850 a shoo-in for quiet environments in need of performance and better functionality.
on the test setup page;
"Corsair Dominator 4GB (3 x 2GB)"
shouldn't it be 2 x 2GB?
shouldn't these cards be able to overclock well, considering how energy efficient they are?
Where's my 5830?
The procesor bottle neck test you presented is just horrible!
For reasons readers will never know is why you left out AA in some of the bottle neck tests but added AA in some the previous benchmarks. For example on page 8 testsing farcry2 had test with AAx4 but not on the CPU bottle neck test, which is what you SHOULD be tsting for!
AA/AF uses the CPU where the graphics card can't handle it and for whatever reason you will come up with to answer me, i think you are simply trying to advertise the Core i5-750 CPU as some sort of incredible cpu that doesn't need overclocking. Are you being paid to do this on purpose are are you just really that shit at making decent review?
umm AA/AF is done purely on the graphics card.
So you're saying that someone forking out small money for a mid range gfx card sees the value in supporting three monitors? Sorry but I really can't see that proposition!
And the DX11 support to me seems a red herring too. Bit-Tech gave a more luke-warm reception and I have to say that I agree with them. DX11 is hardly a sell if the card can only just keep up with the upper-mid range in DX10? Its not like DX11 is going to increase FPS.....
Bitstreaming? Don't know enough to comment!
Thanks Chris.
Another good article.
Although Intel won't want to hear your last sentence I am sure AMD wins either way.
I think that was eskimo's point .. .wasn't it? Be happy with the Q3 earnings report.
We have long know that money spent on better graphics (or a second graphics card in SLI / CF) once you have a quad core runnng at around 3Ghz (Intel i7 or AMD Phenom II) gives much better value return for gaming than anything else.
wheres the overclocking?
Its not like DX11 is going to increase FPS.....Bitstreaming? Don't know enough to comment!
There's already battleforge out there that renders using dx11 subroutines, etc thats showing increase in fps over the dx10 version. So technically, its a game that's taking advantage of a dx11 feature to get higher fps.
http://www.fudzilla.com/content/view/15721/1/
@ Anonymous 13/10/2009 16:37
Perhaps some of the people "forking out small money for a mid range gfx card" are in the market purely for a 3-monitor setup that previously they'd have to use multiple cards for? I don't know.
I would buy a 5770 for an HTPC (the idle power rating / core clock look pretty good to me) but not for anything else.
shouldn't these cards be able to overclock well, considering how energy efficient they are?
Yup. They should.
Worth noting ATI cards seem to have a lot of problems with decoding video streams - in particular there is an open problem with Win7 MCE and BBC HD over satellite.
@ anon
im pretty sure one of the big selling points of dx11 is how much more efficent it is, and how it can offer incresed performance with a higher level of visual fidelity.
so having a dx11 card will most likely prove to allow for higher framerates than a game run with a higher spec dx 10 only card.
I bought this card. My x1950 bit the dust in my last move, and I need a replacement under $200. My mobo only supports a single card, and this is probably the only upgrade I'll do for 2 years or more. At that point, my CPU will likely be a bottleneck (core 2 duo 2.1ghz, overclockable to 2.8 or so).
My thoughts: Of single card setups under $200, this one seems like the best long term value. Especially overclocked, it's as powerful as anything else at this price point, and it has DX11 support. It killed me that I bought my x1950, only to have DX10 come out and instantly obsolete my card... the 5770 won't have that problem. I recognize that I'm giving up a few fps in the short term, but in the long term... this card will be competitive for a longer time in its field.
i have a 5750 and i have oc it to gpu clock 750 and memory clock to 1250 when the card is at 97 % activity the card gets up to 64C! is that dangerous and can destroy my card?
The cards are entirely overclockable dependant on your current CPU/PSU set-up. I would advise buying an aftermarket cooling system also as the card can get incredibly hot when you unleash its potential! I myself have a 5770 and agree that it is a powerful card when combo with a good processor (e.g i5 or higher) excells in performance. And as for the price tag, its also very nice to look at for around £100 for the card (Even lower for the 5750) it is a very wise investment to make for any gaming enthusiast that doesn't want to rape their wallet.