Face-Off: Mass Effect 2

The news that Mass Effect is now a cross-platform franchise has been met with many questions. Just how well can a previously Xbox 360-exclusive title operate on the opposing platform? How well does the Dark Horse interactive comic do at filling players in on the events of the first game? Does the final game justify the various claims being made for it, most notably that it will be the "definitive" edition of the game?

We started to get answers at the tail end of last year when the PS3 sampler first emerged, but BioWare is now on record saying that the demo was old code - something that becomes apparent in our comparison with the review version.

Now we have the review version of the game, supplied on two discs. The first is a copy of the game just like the one you can buy from the shops. The second contains all the DLC you can download from the Cerberus Network as soon as you get the game. What we don't, have, however is the 12GB PSN download of the game - something we hope to look at further down the line.

Let's kick off with the usual raft of comparison assets, beginning with a 720p screenshot gallery and this head-to-head movie.

As you might expect from a game using the rendering underpinnings of Unreal Engine 3, Mass Effect 2 operates at native 720p with no anti-aliasing on the PlayStation 3. There are hints of 2x multi-sampling AA on the Xbox 360, but in common with many UE3 titles this work is carried out fairly early in the rendering pipeline, because subsequent post-processing effects blitz almost all of the effect. The overall impression is that, just like the PS3 version, there is no edge smoothing at all. Other than that, the variances between the two games are mostly minor, aside from the lighting which can be somewhat different at any given point - but more on that later.

In many ways, Mass Effect 2 is a game of two halves - there are the interactive cut-scene elements and then there are the exploration and action sections. That being the case, it's only fair to analyse each of these aspects of the game independently.

Let's kick off with the cut-scenes. If you might remember, in the demo code (now revealed to be two months pre-final), we saw evidence of engine optimisations that suggested that the PlayStation 3 version of the game could be running more smoothly than the Xbox 360 game. However, as the Mass Effect 2 demo-to-review-code comparison reveals, v-sync has been engaged on the final copy of the game and a frame-rate cap has been introduced, which should produce behaviour broadly in line with the existing 360 game.

It's an interesting result. What we see is frame rendering time rising from 33.33ms to 50ms in strenuous scenes - effectively a drop from 30FPS to 20FPS, sometimes sustained, sometimes not - and it affects both consoles. What is curious is that both platforms outperform the other in different scenes, suggesting that there are elements to the rendering process that are more taxing on specific hardware. On the whole though, it seems that the Xbox 360 version edges it, but the overall impression when watching and playing is that both versions are much the same.

What is responsible for the differences in the performance level in some scenes appears difficult to pinpoint. The PS3 version is weak at dealing with transparent alpha effects in direct comparison with its 360 counterpart, and Mass Effect 2's rich atmospherics can smother the entire screen with alpha, sapping performance.

Bearing in mind that the Xbox 360 rendition of UE3 typically outperforms its PS3 counterpart, the elements of performance where the Sony console has the upper hand could very well be down to the fact that it is running on a more recent iteration of the engine. While these games look very similar indeed, BioWare is on record saying that Mass Effect 3 tech powers the PS3 version. That's an extra year of knowhow that's been put into the core rendering pipeline.

Earlier on, we described Mass Effect 2 as a game of two halves: cut-scenes and gameplay are using the engine in very different ways, and on the PC version there are some global settings (such as shadowmap detail levels) that have no impact on the gameplay experience but can cripple the cinematics. So what do we see in the console versions?

The gameplay analysis confirms that the PS3 frame-rate has definitely been capped to 30FPS, just like the Xbox 360 version (we saw anything up to 40FPS and beyond in the unlocked, v-sync-free demo version on PS3). Overall, performance isn't so different across the run of play between the two versions of Mass Effect 2: Xbox 360 frame-rate tends to suffer when Shepard gets a missile to the face, while the PS3 game clearly has issues maintaining 30FPS in the initial clip where - once again - we see heavy use of alpha for the atmospheric effects.

The second clip, with the firefight in the wide-open warehouse, also sees a considerable hit on frame-rate on the Sony platform, once again suggesting that multiple enemies with plenty of action and not a great deal of occluding objects have an undue effect on performance. The Xbox 360 doesn't appear to have anywhere near the same kind of issues in the same section of gameplay.

Having played well into the game, the overall feeling is that both versions have their ups and downs during the run of play, especially in the interactive cut-scenes, where the sudden jarring differences in frame-rate are perhaps most noticeable. However, it is difficult to avoid the conclusion that the original Xbox 360 version of Mass Effect 2 has a performance advantage overall, especially during the exploration and combat sections.