Quoting from OS News:
Guest PC is an emulator of the x86 PC for the Mac OS X platform. We had a quick look at the product and we compared it to VirtualPC 6.1 that we also happened to have in-house.
We used a dual PowerMac G4 1.25GHz with 2 GB of RAM and an ATi Radeon 9200 Pro, Mac OS X 10.3.9 as the host OS and Windows XP Pro as the guest OS. GuestPC supports DOS, Win95/98/ME/NT/XP/2k but there is the ability to potentially boot other OSes too (however we didn’t test this). When creating a new virtual PC image you can select from 300 MB to 32 GB of space for your guest OS, and memory from 32 MB to 512 MB. Then, you click on the “start OS installation” button and it fires up the emulated PC, reads from your CDROM and installs the OS. It took 2 hours to install Windows XP PRO on this machine.
After it got installed, it loaded in about 1.5 minutes to a full desktop. There are some add on drivers that GuestPC can install to extend the experience, and so we got these installed too. GuestPC’s interface is really simple, there are a few icons on the bottom of the OS window showing activity on the peripherals and the CPU load. Using Command+ESC you can release the mouse cursor from the emulated window.
I used Guest PC for over a month and I must say that it’s rock solid. If GuestPC has one great feature, that it is: stability.
I am not happy with the performance though. The kind of performance GuestPC gives me on this dual G4 is pretty much the same performance VirtualPC 5 was giving me on a Cube 450 Mhz 2 years ago. Loading notepad or IE takes a few seconds, while in VirtualPC 6.1 they are almost instant on the same machine (especially notepad). I found GuestPC to be 2-3 times slower than VirtualPC 6.1 in normal everyday usage (IE, office, PaintShopPro etc). I hear that GuestPC really shines when emulates Windows98SE instead on a G5 system. Maybe this is the case, but the reality of the thing is, most Mac users own G4s instead and they are more interested in emulating XP rather than the unstable and old Win98.
Graphics performance is pretty bleak too, there are lots of ugly redraws going on, as the graphics card emulated is a Cirrus Logic 5440 with 4 MBs of VRAM. Funny thing is, I used to actually have one of these cards in “real” life (not under emulation) and they were not too bad in 2D speed at the time, in fact, its 2D speed was better than the 16 MB S3 Trio that VirtualPC emulates. The main problem with the graphics card emulated here is the fact that it only emulates 4 MBs, and so GuestPC does not allow for more than XGA resolutions. I own a good 21″ SONY CRT monitor that can go all the way up to 2048×1536 (and 1600×1200 at 85 Hz), but GuestPC can’t take advantage of it. When I use the “full screen” option, I have to use GuestPC’s OS in XGA, which is a shame as my monitor is capable of a lot more.
GuestPC can’t save the state of the PC like VirtualPC does, but it can use Hibernation. Recovering from sleep with VirtualPC takes 5-8 seconds (suspension to disk, essentially), while recovering from hibernation with GuestPC can take up to 20-25 seconds. And what’s the deal with the “shut down” and “turn off” alert window? What’s the freaking difference on an emulated PC?
And a feature request: support VirtualPC’s image files (or include a utility that converts them to the GuestPC format). This can be an incentive for an old VirtualPC user to upgrade to GuestPC.
In conclusion, I have one thing to say to the GuestPC guys: bring down the price. GuestPC costs $70, but it offers a lesser experience than the $130 Virtual PC 7. Because I don’t see why someone would pick GuestPC over VirtualPC (at least for Windows OS support) or the free Qemu, the incentive should be an even better price. A price at around $40 is more like it. Or, further optimizations must occur.