It's kind of mind boggling just how powerful mundane desktop computers have gotten, let alone server hardware.
Think about it: That 20 core CPU (eg: i7 14700K) you can buy for just a couple hundred dollars today would have been supercomputer hardware costing tens or hundreds of thousands of dollars just a decade ago.
According to geekbench, an i9 4790 processor released a decade ago is ~5 times slower than i7 14700. 4790's go for $30 at ebay, vs $300 for 14700, so price/performance seems to be in favor of older hardware:)
What about power consumption? When running a server 24/7, power is likely to be a bigger cost concern than the one-off cost of purchasing the processor.
Under full load, roughly 100W for the 4790, and 350W for the 14700. Note that both links are for the K variant, and also, both were achieved running Prime95. More normal workloads are probably around 2/3 those peak values.
For a desktop, yeah, you’re generally better off buying newer from a performance/$ standpoint. For servers, the calculus can shift a bit depending on your company’s size and workloads. Most smaller companies (small is relative, but let’s go with “monthly cloud bill is < $1MM”) could run on surprisingly old hardware and not care.
I have three Dell R620s, which are over a decade old. They have distributed storage via Ceph on NVMe over Mellanox ConnectX3-PRO. I’ve run DB benchmarks (with realistic schema and queries, not synthetic), and they nearly always outclass similarly-sized RDS and Aurora instances, despite the latter having multiple generations of hardware advancements. Local NVMe over Infiniband means near-zero latency.
Similarly, between the three of them, I have 384 GiB of RAM, and 36C/72T. Both of those could go significantly higher.
Those three, plus various networking gear, plus two Supermicro servers stuffed with spinning disks pulls down around 700W on average under mild load. Even if I loaded the compute up, I sincerely doubt I’d hit 1 kW. Even then, it doesn’t really matter for a business, because you’re going to colo them, and you’re generally granted a flat power budget per U.
The downside of course is that you need someone[s] on staff that knows how to provision and maintain servers, but it’s honestly not that hard to learn.
I think for server type workloads to get performance improvement estimate it would be reasonable to compare single core performance and multiply by the ratio of number of cores.
On the other hand, the E7-8890 v3 (the closest equivalent to a 14700K in core count at the time from a quick glance) had an MSRP of $7174.00[1].
So maybe I was a bit too high on the pricing earlier, but my point still stands that the computing horsepower we have such easy access to today was literal big time magic just a decade ago.
The RAM also get much larger and cheaper, and it is now possible to have several terabyte (TB) of RAM memory (not storage), in a single PC or workstation. This i7 14700K can support 192 GB RAM but other lower end Xeon CPU W for workstation for example w3-2423 costing around USD350 can support 2 TB RAM albeit only 6-core [1]. But then with not so much more extra budgets you can scale the machine to your heart's content [2].
Think about it: That 20 core CPU (eg: i7 14700K) you can buy for just a couple hundred dollars today would have been supercomputer hardware costing tens or hundreds of thousands of dollars just a decade ago.