Read any article on PC Authority and you'll see that most new PCs come installed with 2GB or more of RAM. It's easy to ascribe this to Windows Vista, which can be sluggish with less RAM, but if you look at the graph (below), it's clear that current RAM quantities fit a surprisingly regular growth curve that's been playing out since long before Vista came on the scene.
|Beyond the 32-bit RAM limit: installed RAM
And if we extrapolate from the curve, we can predict that 4GB of RAM will be standard by late 2010 - just a year after the launch of Windows 7 - with 8GB becoming the norm two years later.
More than 2GB memory: analysing the real performance gains
But what will all this extra memory do? The conventional wisdom is that installing more memory boosts performance, as the OS doesn't rely so heavily on slow disk-based virtual memory. In our feature Memory Stripped Bare, we found that upgrading a Vista system from 512MB to 2GB yielded a 14% performance improvement in our real-world benchmarks.
But this was enough to minimise the effect of disk paging: adding more RAM beyond 2GB had almost no effect.
What about more demanding tasks? After all, in a few years we may commonly be working with ultra-high resolution images and high-definition video. To simulate this, we tweaked our standard Photoshop benchmark to run on the 32-bit and 64-bit versions of Photoshop CS4, rather than the 32-bit CS2.
The 64-bit test, using our Photoshop benchmark
And we replaced our usual collection of four-megapixel photographs with a set of 50 14-megapixel images. On systems with 3GB of RAM, this challenging test revealed no performance difference between 32-bit and 64-bit platforms, in both cases completing in 20mins 40secs.
When we boosted the memory up to 8GB on the 64-bit machine and repeated the process it took... exactly the same time again. Clearly, the 32-bit RAM limit won't have much impact on photo-editing tasks for the foreseeable future.
The 64-bit test, using video
Next we set up a demanding video task in Adobe Premiere Pro CS4: a 1080p input video was chopped up, reordered and spliced back together, with transition, motion and transparency effects.
The resulting movie was then exported as an H.264 file in 720p format. On a system with 3GB the final render took 22mins 20secs; our 8GB system was faster, but only by 43 seconds. It seems video editors also won't need huge amounts of RAM for a while.
Where 8GB of RAM does help
Yet there are specialist cases in which having 8GB or more really does help. If you're running an internet server, for example, or multiple virtual machines, it's possible to devour huge amounts of RAM.
And as the amount of RAM in a typical PC continues to rise, applications will take advantage of increasing resources to offer new features, or faster (but more memory intensive) routines. There's no doubt that sooner or later 2GB will start to feel cramped.
For now, though, we'd advise against rushing out and buying a stack of DIMMs, as current desktop apps simply don't need vast banks of memory. By all means switch to a 64-bit OS - that way, you'll be ready to upgrade when it becomes useful. Until then, let RAM prices continue to fall until there's a reason to buy.
Also in this series, 64-bit Windows guide:
Part 2: Those pesky compatibility issues explained
Part 1: Should you switch?