This is the longest I've ever gone without upgrading the processor and motherboard - the rate of single threaded performance improvement seems to have dropped remarkably from those heady days of the dirt cheap Pentium II Celerons which could be overclocked to 450MHz. Or the early Athlons. Not helped by the hit taken to deal with Spectre and Meltdown.
long ago, i've set my mind to upgrade when new processor come up with double the speed, ram affordable at double the capacity from what i already have. i once or twice upgraded (complete PC) since my first computer (circa 1996) but with my current quad core Q9400 2.66GHz system, its quite difficult to wait for consumer/affordable processor with double the speed (5GHz+) so i've stick with my system for about 10 years now, last time its like 2 or 3 years before the next upgrade. i only since, upgraded my current system to add a little bit ram to max 3GB what XP 32bit can support, add SSD and TB of HDD, replaced the damaged PSU twice, not really requiring large money, from time to time. but if i have to upgrade to new CPU, i have to buy new Mobo, ram, casing, etc the long words for what can be described as simply buying a new computer.
recent post of a member here in a thread on $1000 PC for CADding lead me to that HP Z600/800 system, i thought yeah it fits my spec, more cores, more ram, 3X and 8X respectively from what i already have, and Xeon X5675 3.07GHz is a little bit faster than my current 2.66GHz system, not reaching 2X but nevermind it has more cores and ram. and since its used, the price also fit the bill, so i grabbed one. i think this Xeon workstation came from the same age as my quad core circa 10 years ago, but that time surely the HP Z800 will be very much unaffordable. now i got it at cheaper the cost from what i paid my current system, the only question is how long this branded name is going to last? my custom diy no name brand current system proved working for 10 yrs (with twice PSU replacement), by the right logic, brand name (HP) should at least twice that so theoritically i should have another 10 years with this Xeon, otherwise there is not much to brag about brand name PC system, as i've thought they should be for long time. this Xeon will prove me wrong or right. fwiw ymmv cheers.
btw i lived the life with 3GB of RAM, so i cant imagine some individual will be crippled with 24/32/64GB of RAM, unless in top notch research/simulation environment or IT/server business.