[Alex Kidman is sitting in for Stephen Withers]

Valve Software launched its Steam game delivery service for Mac late last week. If you haven't had a look (and you're in any way someone who games) the install stub is available here (http://cdn.store.steampowered.com/public/client/installer/steam.dmg), but be aware that it will eat up a reasonable amount of data in downloads and updates.

The exact number of game titles available is on the rise - on launch morning 21 titles were listed, up to a total of 64 by the end of the day with promise of more to come - but any way you slice it, it's a great development for Mac fans who are also gamers. The additional cherry of Portal for absolutely nothing doesn't hurt, either.

The potential for Steam to allow developers access to the wallets of Mac games buyers is immense, although it's worth noting that many of the 64 launch titles were already Mac compatible anyway.

Where it gets interesting is when Mac and Windows go head to head in Steam performance terms. Tom's Hardware ran a straight frame rate (http://www.tomshardware.com/news/valve-software-steam-powered-portal-mac,10432.html) comparison of Portal running on OS X and Windows 7, both on a Macbook and a Hackintosh. The results weren't entirely surprising -- Windows is still a "faster" gaming platform, although whether that makes games "better" is perhaps moot.

It does raise as an interesting question is whether Macs are all that well built for gaming in the first place. The graphics capabilities of Macs have come along nicely in recent years, but compared to the visual quality of some of the top-end Windows-only graphics cards, they're still strictly middle-market, at best.

That probably won't matter for the first run of Steam games, which are likely to either be small-run indie titles or Valve's own back catalogue. As offerings expand, however, Steam's claim of "Steam Play" - which allows you to buy a title once but run it on all of your Mac or PC titles - might start to ring hollow if the graphics performance of Macs can't keep up.