The following table details some of the hardware I have used in the PC era. It begins with the venerable Compaq luggable that launched the "clone" wars. I've seen a lot of hardware along the way. In the early era these brands come to mind: Everex, ALR, Northstar, Gateway 2000. Each row in the table shows what were compelling upgrade points along the path. At each step, the blazingly fast new designs left previous generations in the dust. Somehow, what had been a pleasure to use now seemed to be a chore, or too slow to bootup. What had been fast, was now painfully slow. I hope I can add benchmarks to put a mathematical value on each row. Perhaps, by comparing the next row to the previous, or some other baseline.

The genesis for making this table was XP's expiration. That didn't turn out to be as big of a deal as I thought it would. The heartbeep SSL bug made bigger news. XPs overall worldwide usage is estimated as low as 10% currently. The same estimates peg all Linux at 5%. Of course, I use Slackware Linux as my daily OS. XPs expiration forced many to upgrade to marginally better hardware, at least, for those using the Windows platform. I rolled out just over a dozen machines that use i5 CPUs. They have 16G RAM typically. That is a factor of 8 times more over the standard amount that I had incorporated at the previous level (i.e. at Core 2 E6600)

As I was finishing the rollout of the latest generation of PCs with the evolutionary step in operating systems, I had two main thoughts. First, would this be the last hurrah for desktop PCs? Will everyone demand tablets? Will Android and iOS eclipse the Microsoft juggernaut that lasted for a generation? My guess is that the days of PCs as we have known them are limited. Second, I thought how the Windows interface has gotten progressively worse. These are subjective opinions, I know. But I find that Windows 8 is not an evolutionary step that is better than Windows 7. Likewise, Windows 7's interface was worse than XP. I may be an old fogey, but give me consistency for the best productivity. These upgrades have pulled the rug out from under users for no go reason. Again, just my opinion.

8088 clocked @ 4.77 MHz	typ. less than 640k	8-bit compromise of 16-bit 8086; 8087 math coprocessor optional. Used in the Compaq "Luggable".
80286	typ. 1MB, OS limited use beyond 640k	IBM "AT." These machines typically had sockets for 1 MB RAM.
80386 DX @up to 20 MHz	1MB designs still prevalent	included virtual 8086 mode; first to use 32-bit mode; still required a coprocessor for fast math functions; a very important chip. Motherboards could support 1+4MB RAM on proprietary buses.
80486 DX	4 to 8 MB RAM	upgrade to 80386 included on board math coprocessor. Rolled out in Gateway 2000 desktops.
Pentium	First machine outfitted with 32 MB RAM	OS: Windows NT 3.51
dual Pentium Pro @200 MHz	32 to 512 MB	dual CPUs in the "686" era kicked the Pentium's ass. OS: Windows NT 4.0
Celeron w/ 128k L1 cache @800 MHz	128 - 512 MB	budget chip in the "686" line disabled support for multi-CPU in hardware. Motherboard chipset support for SDRAM. These boards were plagued by a bad capacitor problem that caused premature failure.
Celeron single CPU upgrade, w/ 256k cache @1300 Mhz	512 - 1.5 GB	Motherboard offered supported for SDRAM clocks and ecc memory
Pentium 4	Ran hot compared to predecessors
dual Pentium III each w/ 512k cache @up to 1400 MHz	1 - 2 GB	dual chip configuration was good at keeping the machine responsive to the user. Path to memory was showing its age when compared to P4 designs.
Pentium M @up to 1870 MHz	1 - 2 GB	First single core chip to do better than P4. Dell D610 used this chip.
Core Duo	2 - 4 GB	Dual core CPU with good mobile potential. Dell D620 used the T2400.
Core 2	2 - 8 GB	64-bit CPUs spurred the move to 64-bit OSs. E6600, E6750, etc.
i3	4 - 8 GB	22nm architecture saves power on mobile platform. i3-3227U has 4 cores @1900 MHz
i5	16 - 32 GB	i5-3570k, i5-4670k. XP's premature expiration spurred a hardware upgrade to Windows 7, 64 bit at many offices committed to using the Microsoft platform.