ATI Radeon HD 4870 512MB GDDR5

DAMMIT, They Are Back!

Grabbing the headlines this month with a flurry of product launches and announcements on all fronts, AMD looks to be back in the thick of the action. It's still early to give the verdict about some of these developments but they certainly give substance to the upbeat tune that AMD was singing to the media recently. Following our review of AMD's new 65W TDP quad-core Phenoms, we return again today to graphics with the first GDDR5 equipped graphics card, the Radeon HD 4870.

As you would have known from our article on the Radeon HD 4850, the new Radeon HD 4800 series has restored the balance to the Force, we mean graphics scene, and NVIDIA has been forced to get more competitive (and realistic) about its prices. Having a smaller die at a 55nm manufacturing process allows ATI to price its GPUs at such competitive prices, while its strategy of relying on multi-GPU configurations to combat NVIDIA's more powerful single GPUs look quite feasible, at least from the CrossFireX performance benchmarks.

Since we have already looked at the architecture of the Radeon HD 4800 series previously, we won't be covering that here and instead, go right to the card itself and the benchmarks. Of course, before that, here's what you can expect to find on the Radeon HD 4870. Essentially, it is a higher clocked 4850 that uses GDDR5 memory. This new memory format has a higher overall data transfer rate; it's about four times the memory clock so 900MHz on the Radeon HD 4870 works out to be 3600MHz effectively, giving it the most bandwidth of any single ATI card past or present. (While 3600MHz is not exactly accurate, it's a fair way of stating the 'clock speed' such that we can compare ATI and NVIDIA using the same measurement scale.)

The MSI Radeon HD 4870 512MB

We got a pair of these Radeon HD 4870 cards in our labs, just perfect for a CrossFireX setup. Results for that and all the rest are in our benchmark section but before that, let's see what the bigger sibling (literally) of the Radeon HD 4800 series bring to the table.
The reference Radeon HD 4870 comes with a familiar looking dual-slot cooler.
Removing the cooler from the card, you can see that it has two heat pipes, connecting the aluminum radiator to the copper base. A 80mm fan sucks cool air from outside and forces that over the heatsink.

The single slot cooler on the Radeon HD 4850 was good for just one thing: saving you an expansion slot if you're in the CrossFire mood. The 4850 itself was running much warmer than we had expected and though one could always point the finger at the cooler, ATI probably felt that it was worth the trade-off. So how about the dual-slot and beefier cooler on the 4870?

Well, it's slightly better. The fan will spin at 100% like quite a few other high-end graphics cards at boot up but the noise wasn't too bad once you get pass that stage. It's definitely audible and the temperatures too were quite high. It's not as high as the 4850 but it will still scorch your fingers if you touch certain parts. Consisting of two heatpipes with a solid chunk of copper for the base, it's quite a hefty heatsink and hence not exactly a card you can toss around easily.

Clock speeds on the Radeon HD 4870 are naturally higher, with the RV770 core at 750MHz, compared to 625MHz on the Radeon HD 4850. Memory differs the most of course, with the GDDR5 (from Qimonda) on the 4870 giving it an effective 3.6GHz clock speed and with ATI claiming that the new memory format can go up to 5GHz in the near future. Most of the Radeon HD 4870 boards you'll find now are likely to be reference designs and will look similar to the ones we have shown here, though overclocked ones have been announced by BFG and Diamond Multimedia.


The Radeon HD 4870 comes with two 6-pin power connectors and requires a decent PSU of at least 500W. If you're planning CrossFire two of these GPUs, a minimum PSU rating of 600W is recommended.
The rear I/O outputs on the Radeon HD 4870 are the usual ones, a pair of HDCP compliant DVI outputs and a mini-DIN. There's also the exhaust vent for the warm air passing from the heatsink.

Two CrossFire connectors mean that up to four 4870 cards can be linked but that would require a very high-end system.

The Best is Yet to Come

As our title suggests, the top 'single' GPU from ATI is yet to make its debut. The R700 technically consists of two RV770 GPUs in CrossFireX mode, so one can already take a rough estimate of its performance from our CrossFire results here. Of course, having two cores on a single PCB will no doubt save users an expansion slot and for the novice, it's probably easier to install and setup, not to mention it does not require a CrossFire compatible board. So those on NVIDIA motherboards may 'defect' without needing to get a new motherboard too. With the number of Intel motherboards in the market, there's hardly a lack of choices if you go the dual card route.

Our benchmark results showed the reason why reviewers and users have been crowing about the new Radeon HD 4800 series. We have already seen the capabilities of the Radeon HD 4850 earlier but the 4870 model is certainly a notch higher and you'll find significant improvements, sufficient to justify the roughly US$100 premium going from the 4850 to the 4870. CrossFire performance also seemed to have improved with the newer drivers we tested and with ATI committed to releasing drivers regularly, this is good news for enthusiasts.

The closest GPU from rivals NVIDIA in terms of performance is in most cases, the GeForce GTX 260 and at its listed retail price of US$399, it may find the US$299 Radeon HD 4870 too aggressive in pricing and performance. The GTX 200 GPUs does appear to have rather impressively low idle power consumption for their size, though their peak consumption is higher than ATI. In the end, it's the relatively warm core temperature readings that we got for the Radeon HD 4800 series that's stopping us from giving them a perfect score. The results too in a few cases still favor the NVIDIA equivalent, but for the most part, ATI has managed a strong showing of performance blended with a great price tag.

NVIDIA has led the industry with performance and price competitiveness for a couple of generations now, while ATI relied on supporting new standards and features that have generally being underused by developers (tessellation and DirectX 10.1 comes to mind on this generation) along with the excellent Avivo HD features to distinguish its products. Finally, the red team has produced a GPU worthy of competing and looks to reap the benefits of lower manufacturing costs with its smaller die. For consumers, what matters is the bottom line and with prices like these (and dropping too for the Radeon HD 4850), it is good times ahead.