AMD ATI Radeon HD 4870 1GB

Rounding Up…

The Radeon HD 4870 1GB is an interesting card in many respects, but the main reason that it has piqued our interest is the fact that there are some performance advantages to be found as a result of the increased memory footprint. Traditionally, we’ve found that an increased memory size doesn’t necessarily translate into a massive performance advantage—at least not one where you can consistently see differences that are, let’s say, relevant.

Probably the last time we saw something similar to this was when Nvidia introduced the GeForce 8800 GTS 320MB – a card that carried many of the GeForce 8800 GTS 640MB’s performance characteristics, as long as you didn’t turn anti-aliasing on or play games at high resolution. When you reached the break-off point with the GeForce 8800 GTS 320MB, it was like jumping off a cliff – performance literally died in quite spectacular fashion.

Unlike the GeForce 8800 GTS 320MB though, the Radeon HD 4870 512MB doesn’t jump off a cliff – the performance is still there consistently right the way up to 2,560 x 1,600 with high levels of anti-aliasing. It’s as if AMD has better local and external memory management – it’s able to optimise what data needs to be in which memory pool so that the performance hit normally associated with using system memory just isn’t quite as profound as it can be.

Where the additional memory on the 4870 1GB helps is that it reduces the number of occasions where system memory needs to be used. And the result is some fairly decent performance increases almost across the board. Sure, the increases are not going to set the world on fire, but they are there in certain scenarios—especially when high levels of anti-aliasing are enabled.

These performance differences range from around five percent right the way up to 15 percent in worst-case scenarios that are, most importantly, still relevant. The differences we’re speaking of here are at frame rates that are playable – we’re disregarding any instances where the frame rates simply aren’t high enough. With that said though, some titles, like Half-Life 2: Episode Two in particular, don’t see significant performance benefits until we started pushing pixels out at 2,560 x 1,600 and not everyone owns a display that big.

And, more to the point, we wouldn’t recommend pairing a single Radeon HD 4870 1GB (or 512MB version for that matter) with a 30-inch monitor. At the very least, you should be looking at a Radeon HD 4870 X2 or a pair of GeForce GTX 260s to power a display of that size. The target market for the Radeon HD 4870 at the moment, then, is really for those with 24-inch panels—or at least screens with a 1,920 x 1,200 native resolution—so that’s where we should really be analysing the data.

Crysis in DirectX 10 mode showed us virtually no benefit at this resolution, which is really down to the fact that the additional memory makes very little difference when AA is disabled – we were unable to get playable frame rates with even 2xAA enabled when all in-game details were set to ‘high’. In DirectX 9.0 mode, things didn’t really change at this resolution – frame rates with AA enabled were still too low to achieve playability but were fine without AA. For those that are happy not running the native resolution, we witnessed a respectable six to eight percent increase in performance when 4xAA was enabled at 1,680 x 1,050 – this takes the game from being marginally playable to relatively smooth, as Crysis feels quite fine with relatively low frame rates that we’d baulk at in most other games.

In Call of Duty 4, the Radeon HD 4870 1GB delivered frame rates that were approximately eight percent higher than what we recorded with the 4870 512MB at 1,920 x 1,200 with 4xAA enabled. While this represents a reasonable increase, the frame rates are already pretty high to start with – it would be of benefit in COD4 Multiplayer, though.

GRID and Half-Life 2: Episode Two are both CPU limited at 1,920 x 1,200—even with AA enabled—so the benefits in these titles are small. However, both World in Conflict and Devil May Cry 4 showed some respectable performance increases – the former showed an eight percent performance improvement with 2xAA enabled while the latter increased frame rates by approximately 13 percent with both 4xAA and 8xAA applied.

Final Thoughts...

At anywhere between £187 and £200, including VAT, the Radeon HD 4870 1GB appears to represent pretty good value for money. It’s not only cheaper (and better-performing) than the various GeForce GTX 260+ cards on the market, but it’s also not that much more expensive than the pre-overclocked GeForce GTX 260s out there as well. In most scenarios, it’s actually not too far behind Nvidia’s GeForce GTX 280 – a card that costs around £80 more.

When you compare it to the Radeon HD 4870 512MB, which retails for around £170 these days, you still appear to be getting a good buy as well. It costs around eight percent more and in some circumstances you’re getting performance increases much bigger than that, even at 1,920 x 1,200 – the screen resolution this card looks to be targeting. Of course, there are scenarios where there will be little-to-no benefit, but they’re to be expected anyway – not all games are completely GPU bound and in those games you’ll see very little benefit from a faster graphics card, period.

Even at 1,680 x 1,050, there are scenarios—like in Crysis—where the additional memory delivers higher frame rates and with most of this year’s blockbuster releases still to come, we’d argue that the Radeon HD 4870 1GB will become even more relevant at this resolution as well, as graphics demands are likely to increase with games like Far Cry 2, Fallout 3 and Mirror’s Edge right on the horizon.

In short, if you like playing games with lots of AA turned on, you’ll love the Radeon HD 4870 1GB.

• Features
• x
• x
• x
• x
• x
• x
• x
• x
• x
• -
• 9/10

• Performance
• x
• x
• x
• x
• x
• x
• x
• x
• x
• -
• 9/10

• Value
• x
• x
• x
• x
• x
• x
• x
• -
• -
• -
• 7/10

• Overall
• x
• x
• x
• x
• x
• x
• x
• x
• x
• -
• 9/10

What do these scores mean?