Overclocking

We overclocked the Sapphire Radeon HD 3870 Atomic using RivaTuner version 2.06 to increase the clock speeds and Crysis under DirectX 10 mode to test for stability.

We increased the core and memory speeds together, increasing 5MHz at a time until the card crashed. Once it crashed, we then dropped back to the previous setting and ran a two-hour stability test to check that the card was completely stable over prolonged periods of load.

As a quick reminder, Sapphire's factory-overclocked card comes with an 825MHz core clock, while the memory is clocked at 2400MHz (effective).

After a couple of hours of tweaking and stability testing, we found that we were able to increase the core speed to 875MHz and the memory to 2512MHz (effective). This represents increases of 50MHz or 6.1 percent and 112MHz (effective) or 4.67 percent respectively.

In terms of raw performance, the increased clock speeds gave us an extra two frames per second (7.5 percent) in Crysis at 1680x1050 0xAA 0xAF with Very High Shaders and Water quality, while all other options were set to high.

Temperatures

Impressively the Sapphire Radeon HD 3870 512MB Atomic is nine degrees cooler at idle, but what’s even more impressive is the fact that it is also ten degrees cooler under load! There are no two ways about it – that’s a pretty incredible result for Sapphire’s VCT cooling solution. Woah!

Final Thoughts...

Sapphire’s Radeon HD 3870 512MB Atomic is a ground breaking product in many respects, but sadly where it falls short at the moment is on the performance side of things. From what we understand, since the launch of the Radeon HD 3870 X2, the RV670 chips are suffering from even higher demand than they were before. This has resulted in the prices of the standard cards increasing slightly, and bringing them more into line with Nvidia’s GeForce 8800 GT.

This is a problem for AMD/ATI, because the chip just isn’t fast enough—even when it’s overclocked like Sapphire’s excellent example we have here today. Hopefully, we’ll see the price come down again very soon because that’s ultimately having an effect on the price of the card we’re reviewing here today. Sapphire says that the card should be hitting a £165-170 price point, but retailers are currently asking customers to pay up to £200 (inc. VAT), which puts it almost on price parity with the appreciably faster GeForce 8800 GTS 512MB!

The cheapest we’ve found the card for is £188 (inc. VAT) on Dabs, which is on the expensive side, but it sounds easier to stomach than the £200 other retailers are expecting customers to pay for this graphics card. Sapphire was quick to point out that the card is a limited edition—more of a technology showcase if you will—than a card it expects everyone to rush out and buy.

What we can take away from this though is the fact that there has been some true innovation here—something that we don’t see all that often from add-in board partners. The technology that Sapphire has showcased here is nothing short of awesome – it not only looks good on paper, but also works incredibly well in practice as it managed to knock ten degrees off the load temperatures of a reference Radeon HD 3870! What’s more impressive though is the fact that Sapphire’s card is running at much higher clock speeds than the reference card.

Interestingly, during my conversation on the phone with Sapphire’s Global PR Director, I was told that the company is expecting to roll out the VCT cooling technology onto more affordable cards that are mass produced. I don’t have any more details on what Sapphire is doing in terms of pricing and clock speeds on these cards—or even which models for that matter—but I have to say I’m excited to see what kind of price point it can hit with a card using this cooling technology that isn’t only available in limited quantities!

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