That's why I tend to stick to looking for combos on ebay. If they've already got it installed and working there is a much better chance of success that it won't be a dud after purchase.
Still, be aware that motherboards have many points of failure, I doubt any of them will test all the possible IO slots, so you might be in for a surprise a few years down the road. My rule of thumb is to factor in the potential failing of the motherboard (having to replace it immediatly or a couple of years in), if it's still worth it, then it's a good deal.
In my observations, used Threadrippers are often too expensive vs. retail, but I've rarely looked at bundles including memory, which may help the value a lot.
Back around 2021-2022 I was looking at many Xeon deals, like LGA2066 and buying 2-3 sets of CPU/motherboard/~128GB RAM, which at the time would cost ~$500 + shipping and tax for each. This is the kind of deals I think would be worth it, with the risks factored int. I was also looking at LGA3647 at the time, as some of those CPUs could be had for dirt cheap, and potentially buying a brand new motherboard to go along with it.
And this is a point that I would like to make; if you find a CPU that's a great deal (and tested), buying a new motherboard might be an option too. Buying CPUs and RAM in general is fairly low risk, and with RAM if one stick is bad you can of course get the system running until you get that one stick replaced.
But don't forget, discounts do happen in retail too, like 20% off on a CPU sometimes.
7960x + MB (6 slots, 2 mini SAS) + 256GB DDR5-5600 ECC + Cooler + free shipping is a perfect fit for me - estimated $3280 including tax…
It depends on what comparable products would cost in retail in your country. If it's used, you should expect a
good discount.
Comparatively if I consider my 7950x at the moment the move to 7960x gives the me more MT and about the same ST. The Zen2 platform at about the same MT performance level with 3970x (with more cores) and about a 1/3rd less ST at about half the general total system cost of 7960x still just doesn't seem worth it. I dislike the idea of stepping down to Zen2 threadripper because since stepping up from 5950x to 7950x my work in VM's everyday feels really snappy now and comfortable.
(quick rant begin) If AM5 motherboards had some more functional PCIe slots I probably wouldn't bother racking my brain on this.
Single threaded performance is certainly very important, but the actual impact of it vs. multithreaded performance is challenging to benchmark, and is
highly workload specific. Never put too much emphasis on synthetic benchmarks. And don't forget, the extra capabilities of a workstation will probably lead you to using the system more heavily, something which the mainstream system would be slowed down to a crawl. Most workstation users generally want the right mix of both; fast snappy cores and handle a variety of loads. And as most real workloads are rarely purely single threaded, a
proper workstation benchmark should be more "mixed", like 4+ heavy threads, a few medium and lots of light ones, and
this is where you see the real world difference; while the mainstream CPU excels with a single thread, with mixed loads it will throttle heavier than a workstation CPU. This is why workstations "feels" more performant and responsive, because they are, it's just hard to accurately measure. So while many think workstation CPUs are only for those with massive batch loads, they are also great for "normal" multitiasking, like running a VM, some productive applications and a browser, without a noticeable slowdown. Try the same on a mainstream system and compare, you'll see a huge difference. Having lots of extra RAM and unconstrained performance from SSDs will also have some impact here.
My advice for you would be this;
Either buy a 7960X (bundle) at a
significant discount,
or wait for Zen 5 Threadrippers and buy retail with 256 GB DDR5-6400(probably) etc.
