signmeuptoo, cost to specs he'd likely be spending as much as a refurb 21.5" iMac(May 2011) on a workstation grade PC(~$900-950 without a SSD). If you cut back to a cheaper nVidia GeForce/Quadro card, two WD Blue 1TB and some cheaper RAM(ex: Kingston HyperX) you could pull it off at ~750-800. Keep in mind since WD Blue drives 1TB+ have 32/64mb cache, you could/should skip the WD Black series. Personally I only use WD Black drives on notebooks, WD Blue desktop drives are very reliable at 24/7 usage(I average 4-5yrs before I do early retirement).
said by norwegian:And hardware it seems. Looking at the specifics for Windows here there seems quite some restrictions to hardware, firmware etc.
Also here for graphics cards.
Although all Apples with i5 here suggests the cpu is fine, it maybe more as pointed out about the motherboard?
The graphics card is less of a factor on a PC/Mac unless an IGP starts to take a huge chunk of shared memory to power a high resolution monitor--keep in mind that technote is for ProTools HD which is used by movie/5.1 audio studio work who use multi-monitors(30"), regular ProTools 10 has similar requirements of v9 but you'd still want to lean towards nVidia GeForce/Quadro for quality drivers. 8-16GB of RAM is enough to avoid the wraith of Intel IGP pulling too much memory(768mb is the most the 3000/4000 will share with twin 27" monitors connected to a Mac mini).
I've used Pro Tools M-Powered 8 & 9 on a 13" 2010 MacBook Pro(nVidia 320M), however I had to replace the slow stock 5400 RPM HDD with a 7200 RPM drive, pull the DVDRW drive to fit a 2nd 7200 RPM HDD(recording storage) and max out at 8GB RAM for recording duty. (I've considered the Mac mini server route after seeing a small studio with such a setup)
Digidesign/Avid never/rarely certified "consumer" Macs due to slower stock HDDs, single HDD & lousy amount of stock RAM. I've used Pro Tools on iMacs off & on since OS 8.5 era, typically you need to partition a HDD to create a "scratch partition"(similar to Photoshop users) and is a very stable platform with a single HDD. With Thunderbolt solutions, lack of PCI/PCIe/ExpressCard slots on an iMac/Mac Mini/MacBook Pro is no longer a negative aspect.
Music recording is just as expensive as AutoCAD setups... sadly anyone who is stuck using ProTools either is stressed out for PC options or settles with a Mac. Thankfully there are other recording software companies with less anal "requirements" such as Reaper, Ableton, Cubase, etc. Avid ProTools is just as evil as the RIAA.