The things that are going to make the biggest differance to your Resume from Hibernation mode assuming like me you have a XP Pro install SP2 (Windows Updates), No bull**** installed, Defragged, and optomised system such as running "Bootvis" at least are:
Rapid POST Capable
RAM Type (DDR vs SDRAM)
SATA or IDE (ATA100 or ATA133)
Again this is the same as your IDE Controller
SATA or IDE (ATA100 or ATA133) (HDD Cache 8 or 16MB)
Faster the Better
AMD over Intel for onbaord Memory Controller.
Rapid POST as on some Intel Boards i have makes a big differance. This shaves several seconds off the POST time when compared to the P3 board i use, before my PCI Nvidia has finished POST (NVIDIA -> IBM POST -> BOOT) the Intel Rapid BIOS (POST) system is finished POST and booting XP, additionally memory 512MB of SDRAM (133MHz) is obviously slower than 512MB DDR of any speed, even 266MHz DDR never mind 33MHz Memory but esp if you run Dual Channel Mode, with respect to HDD again faster is better with a SATA HDD running at 150MHz being faster than an IDE running an PATA 100MHz Interface, on the CPU front i still think the AMD XP-M is a winner here if you can get your hands on one as the onboard Memory Controller is just going to help things all the more, and the low power requirments are always a plus.
Boot from Hibernation is one thing and one thing only for the majority of it and that is a Read from HDD to RAM operation, (Hibernation File -> Processed to Memory by Windows),b the faster the components in your PC the faster your POST and faster windows will perform the actual task of restoring the sesson from the Hiber.sys file on your HDD. It is simply about the moving of the data from the Hiber.sys file from your HDD to RAM and its implementation by Windows XP, this is all about the RAW Processing POWER of your System.
Additional thing like those mentioned will also help such as setting manually as many setting in the BIOS as you can, a few milliseconds here and there make all the differance, most people should be able to see under twently seconds resume from hibernation on any decent P3 board with a 1GHz CPU.
Also having as few process etc as you can on boot will help, applications running when you boot your pc, processes even though you don't use them, these all still have be suspended and then resumed, all these things take time, no one needs the '"Windows Firewall Service for example or the ""Messanger" service either as two examples yet both runon probally 90% of machines, also disable the Onboard LAN and its Boot Loader in the BIOS and make sure your HDD is your Primary boot device in your BIOS, tell your BIOS not to look for anything else such as USB boot devices, as i said before optimise your BIOS and XP Startup Applications and Services (Start -> Run -> type MSconfig -> Click Ok), to disable services it (Start -> Run -> type Services.msc -> Click Ok)
The more you can turn off the better, disable your Wireless when not using it to stop XP looking for LANS on resume also, really how well you will do one this is greatly influanced by your know how when it comes to gthe optomisation of the BIOS on a PC and the optimisation of Windows itself with IT people having the destinct advantage here. And RUN Bootvis for GODS SAKE.
Sorry if this seems a bit long winded but it needs to be spelled out for once and all.