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Sapphire's HD 4870 beats every 9800 GTX

by on25 June 2008

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Review: HD 4870
GDDR5 leaves quite an impression


The day
has finally come when ATI is ready to introduce the full power of its RV770 chip. As we've said many times before, RV770 is a DirectX 10.1 chip developed in 55nm with 965 million transistors and most importantly, with support for GDDR5 memory.  It’s also important to mention that RV770 has 800 stream processors, 40 texture units and 16 render back ends.

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The memory is the key difference compared to the Radeon HD 4850, RV770PRO-based card. The GDDR5 will definitely confuse the hell out of you, as it actually works at 900MHz but in theory it will match the performance of 3600MHz GDDR3 memory. The answer why is quite complex, as officially GDDR5 from Qimonda works at 900MHz. A single 64Mbyte chip has 32 data lines, which gives you 32x900MHz or 26.8 Gigabits /sec of commands.

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For read and write operations we have doubled that number, or 56.3GigaBits/second as the clock rate for these operations are twice higher as the command clock. With the eight parallel chips you'll find on a 512MB Radeon HD 4870 you can achieve 107.2 Gigabytes/ second, thanks to Dual Data Rate technology. If you are confused, don’t worry, so are we; but just keep in mind that Radeon HD 4870 has 107,2 GB/s of bandwidth while the GDDR3 based Radeon HD 4850 has 63.6GB/s, or some seventy percent less bandwidth.

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ATI's RV770XT, the chip behind Radeon HD 4870, works at 750MHz and needs a dual slot cooler, while the GDDR5 memory works at 900MHz, which is much faster than GDDR3 memory that is clocked higher. The memory bus is 256-bit wide and this is the same compared as on the old RV670 chip. The RV770XT and PRO are the same chips, but ATI clocks the better yielded chips to 750MHz, calls them XT and matches them with GDDR5, while the slower chips end up with GDDR3.

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The die size is 256 square millimeters, which is a fraction compared to GT200 that measures a monstrous 578 square millimetre. The card itself looks very similar to Radeon 3870, but this time it has two six-pin power connectors and just like the HD 3870, this card has two Crossfire connectors on top of the card, two DVI outs and S video out. Naturally, the card supports PCIe 2.0 standard, but it should work just fine with PCIe 1.1 boards.

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The Sapphire HD 4870 512MB card comes with 3Dmark06, Rubi ROM, Power DVD 7, Cyberlink DVD suite user manual and the version we’ve got had 2GB Sapphire branded USB stick, which is a nice touch. The retail box also comes with two 6-pin power connectors, HDTV cable, DVI to HDMI, DVI to VGA and Crossfire bridge. Sapphire's card will cost $329 in American e-tail, while it should be selling between €229 to €249 including VAT in Europe, although we already found one listed at just €216.

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During testing, the card was heating up to 80 degrees Celsius and was stable with these temps, but at the same time it was not that noisy.

It's hard to put into words, but it was not the most quiet card we’ve heard, although it came very close. The only thing we really hate about all ATI hardware is the fact that fan rotates insanely fast when you boot a machine. We hate this, as the machine is incredibly noisy and this gets very annoying in the evenings. Does the cooler fan really need to rotate at the highest speed at startup?

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Testbed:

Motherboard:
EVGA 680i SLI (Provided by EVGA)

Processor:
Intel Core 2 Duo 6800 Extreme edition (Provided by Intel)

Memory:
OCZ FlexXLC PC2 9200 5-5-5-18  (Provided by OCZ)
        during testing CL5-5-5-15-CR2T 1066MHz at 2.2V

PSU:
OCZ Silencer 750 Quad Black (Provided by OCZ)

Hard disk:
Seagate Barracuda 7200.9 80GB SATA (Provided by Seagate)

CPU-Cooler:
Freezer 7 Pro (Provided by Artic Cooling)

Case Fans:
Artic Cooling - Artic Fan 12 PWM
Artic Cooling - Artic Fan 8 PWM

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Futuremarks


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We managed to get some Geforce GTX 280 scores and to see how ATI goes against this two times more expensive competition, just for the sake of argument.

At default 1280x1024 3Dmark06 still scores best on Nvidia's GX2, a dual chip card. It is surprisingly interesting that Sapphire HD 4870 ends up faster than all Geforce 9800 GTX cards, including the super overclocked Black Edition and runs some 300 points slower than the almighty Geforce GTX 280. With new memory, HD 4870 scores more than a thousand points in this test.

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In Company of Heroes, the new memory and higher clock are just enough to win against every Geforce 9800GTX. The Radeon HD 4870 is even faster than dual chip 3870 X2 card, which is impressive, but it does lose to both GTX 280 and 9800 GX2 cards by 20 FPS to GX2 and almost 35FPS to GXT 280. Radeon HD 4870 is about twenty percent faster than Radeon HD 4850 in this test and it always wins against any 9800 GTX, including the overclocked ones.

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Crysis is a nice surprise, as Radeon HD 4870 scores close to GTX 280 in this game, at least in lower resolutions. It is just faster than any Geforce 9800 GTX and it is always massively faster than Radeon HD 3870 X2 dual chip card. It is impressive that Sapphire 4870 is faster or almost the same as Geforce 9800 GX2 dual chip card. Sapphire 4870 is up to thirty percent faster than Sapphire 4850.

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Due to a very limited time, less than 24 hours since we got the card we managed to test good old FEAR and we can say that this game really fits this card. Radeon HD 3870 X2 is still dominant, but 4870 wins or gets tight against GTX 280 and GX2. In FEAR Radeon 4870 ends up on average 10 percent faster than 4850 and both cards are always faster than Geforce 9800 GTX, including the overclocked ones.

Conclusion

Sapphire's HD 4870 is one impressive card. ATI shows that it can be the leader again. This is the first card to use GDDR5 memory and ATI just added one cool marchitecture to its portfolio.

This card continues the 55nm leadership and also supports DirectX 10.1, while not even Nvidia’s flagship, the Geforce GTX 280, upside down naming edition, doesn’t support any of these marchitectures.

When it comes to performance, Radeon 4870 wins against G92, including the chip clocked to 760MHz which gives an interesting implication that Geforce 9800 GTX+ is likely to lose from Radeon 4870. The alternative is that Nvidia might increase the clocks to beat ATI but it will be close.

One thing is certain, we are sure that Radeon HD 4870's current performance leadership in the sub-$300 market means a certain price war and you, our bellowed readers, will benefit, as the prices will have to go down.

Geforce GTX 280 is clearly faster, but not as much to justify twice as much money. For the price of a single Geforce GTX 280 you can buy two Radeon 4870s and get a decent lunch while you're at it.

In this category, we can highly recommend this ATI masterpiece, and Radeon HD 4870 is probably the best card money can buy in sub-$300 / €229 euro price range, but we are sure that this price will go down, sooner rather than later.


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Last modified on 10 July 2008
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