Original URL: http://www.theregister.co.uk/2009/10/28/review_graphics_amd_ati_radeon_hd_5770/

AMD ATI Radeon HD 5770 and 5750 DirectX 11 GPUs

DX11 gaming on the cheap?

By Leo Waldock

Posted in Hardware, 28th October 2009 13:02 GMT

Review AMD's Radeon HD 5770 and 5750 are the mid-range members of the new HD 5000 DirectX 11 graphics chip family. They're fabbed using a 40nm process, just like their bigger brothers.

AMD ATI Radeon HD 5770

Sapphire's HD 5770: reference Radeon HD 5770 design

But the number of transistors in these mid-range chips - codenamed 'Juniper' - has been reduced by just over a half, from the 2.15bn in the 58x0 design, codenamed 'Cypress', to 1.04bn. The area of the chip has also been quartered, from 334mm² to 166mm².

Armed with that information, you won’t be surprised to learn that the number of unified shaders in 5770 has been halved too. Which is to say that the 5870 has 1600 shaders and the 5770 has 800. The 5750 has 720.

When it comes to clock speeds, the 5770 has the same 850MHz core speed as 5870 while the 5750 runs at 700MHz, which is slightly slower than the 5850's 725MHz frequency. The specification of the memory breaks with tradition as the junior 5750 and 5770 use 1GB of GDDR 5 just like the grown-up 5850 and 5870. In the past, we've been accustomed to mid-range chips that use slower memory than their high-end siblings do. The high-end chips use a 256-bit memory controller while the new mid-rangers settle for a 128-bit controller.

It's a safe bet that AMD has chosen these shader counts and clock speeds to ensure there is a clear distinction between each member of the HD 5000 family and it also results in a neat cascade of prices.

AMD ATI Radeon HD 5750

Radeon HD 5750: cool runner

The 5870 sells for £299 or you can buy the 5850 at a more reasonable £199 and still get masses of DirectX 11 performance. The 5770 slips in at £132 and the 5750 costs £110. The prices put the new DX11 chips head-to-head with Nvidia’s DirectX 10 GeForce GTX 260, which typically sells for £125-160.

On the face of it, this is an unfair fight as we are comparing brand new AMD technology with Nvidia's previous-generation offering. But Windows 7 has been launched so the new age of DirectX 11 is here. Alas, Nvidia doesn’t have its DX11 chip ready and, as far as we can see, it won’t be here until Q1 or possibly Q2 2010.

AMD ATI Radeon HD 5770

There’s another way to look at the 5770 and that’s as a direct replacement for the 40nm DX10.1 Radeon HD 4890. Both chips have 800 shaders, a core speed of 850MHz and connect to 1GB of GDDR 5. The introduction of the 5770 has driven the price of the 4890 down from £229 at launch to a mere £150 today which means that it's only £20 more expensive than the 40nm 5770.

In appearance, the 5770 looks very similar to the 5850 and 5870, and has two DVI outputs, one HDMI and one DisplayPort on the dual-slot bracket. It's slightly shorter - 215mm to the 5850's 240mm length. The shroud over the cooler is present and correct and the single PCI Express power connector continues to be tucked in one of the intakes for the shroud.

The 5750 is shorter still - 180mm - and the cooler is very basic, looking much like the sort of thing we have seen on previous budget graphics cards. You still get dual DVI, one HDMI and one DisplayPort.

The power rating of the new mid-range cards is impressively low. At idle, the 5770 draws 18W which rises to 108W under load. The figures for the 5750 are 16W and 86W, respectively.

AMD ATI Radeon HD 5750

We tested the 5750 and 5770 graphics cards - both from Sapphire, but they're standard reference-design cards just like you'll get from other vendors - on the same Intel Core i7 system that we used in our 5850 and 5870 review. We also added the 4890 into the mix. The 5770 was consistently slower than HD 4890, which is presumably a result of the reduced-bandwidth memory controller. On the bright side, the 5770 drew an impressive 80W less than 4890 under load, and we can only speculate that the 5770 will gain some performance when we have proper DX11 games to play. For the time being, you get an extra six frames per second in Battle Forge and Far Cry 2 if you stick with the 4890.

3DMark Vantage Results

AMD ATI Radeon HD 5770

Longer bars are better

Battle Forge v1.1 Results
1920 x 1080, Very High Quality

AMD ATI Radeon HD 5770

Average Frames per Second (F/s)
Longer bars are better

Far Cry 2 v1.0.3 Results
1920 x 1080, Ultra High Quality

AMD ATI Radeon HD 5770

Average Frames per Second (F/s)
Longer bars are better

System Power Consumption

AMD ATI Radeon HD 5770

Power draw in Watts (W)

The performance of the 5750 is lower than that of the 5770 to the tune of 20-25 per cent which is a big step down for a relatively small reduction in price. On the face of it, the 5750 misses the mark and we'd recommend the 5770 to any gamer on a budget that won’t stretch to a £199 5850.

AMD ATI Radeon HD 5770

Better for casual gamers than serious players?

This is only part of the story because we saw something rather interesting when we added Nvidia GTX 260, GTX 280 and GTX 285 cards to the mix. The performance of the mainstream GTX 260 is essentially identical to the 5770, which has forced Nvidia to drop the price of the 260 to £125. The GTX 280 has been replaced by the GTX 285, which can be bought for £219. But even at this reduced price, it struggles to comprehensively demolish the 5770, which is much cheaper. More worryingly for Nvidia, the 280 gets trashed by the slightly cheaper 5850.

We have previously run 3DMark Vantage on an Asus Matrix GTX 285 using the same Core i7 system and this £289 graphics card was beaten hollow by the £299 5870 and also by the £199 5850. Our view is that you'll struggle to play the imminent crop of DX11 games at high image quality settings on the 5750, and the 5770 isn’t much better. We blame the 128-bit memory controller for this failing as the 4890 is significantly better. If we could have the power saving features of the 5750/5770 combined with the performance of 4890 we would be happy.

As things stand, we can't recommend the 5770 to serious gamers - we suggest the more expensive 5850 instead.

Verdict

The Radeon HD 5770 comes close to being a superb graphics card, but AMD has throttled its performance. We suspect that the company is trying to segment the market to leave Nvidia without a leg to stand on and in that respect it has succeeded. Unfortunately, it hasn’t delivered the mid-range graphics card that caters to gamers on a modest budget. ®

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