The only way to compare two computer is to compare their performance not necessarily what they have in them.
My PC has an 8 core i7, with 24Gb of triple DDR3 memory, with three Western Digital Cavier black drives (6TB), silent cooling fans and running a pair of 1920 x1200 monitors. With this I run upto 3 instances of VE Pro, with typically around 20 to 30 libraries, mainly VSL, some EW and Kontakt and BFD as well, most of my VSL instances have 9 to 12 articulations loaded ready to go - and it all runs together (all through MIR as well), and not only that, but I often have Sibelius loaded as well with it's memory hungry library (and that has Vienna Convolution reverb running as well)..
It has never ran out of memory or glitched at all, it is ran as a slave PC, my other PC runs Cubase via VE Pro. So this PC is more than powerful enough to run anything I throw at it, and I do use big full very active orchestrations.
You don't need Xeon processors, SSD drives, use RAID configs, or waste money on Macs (or branded PC's) to have a very powerfull flawless computer. My working PC is proof of that.