If you want Epyc go for it. The motherboards can be quite expensive though.
replySo what I am trying to say, industry took a wrong turn. Instead of moving to over-priced DDR5, they should just make even cheapest CPUs support 8/16 DDR4 channels. Because a 32Gb DDR5-4800 module costs $360, and two 32Gb DDR4-3200 modules cost $320, so you get twice more size, more bandwidth and it costs you less. DDR5 is just a rip off.
replyEach memory controller interface is a not-insignificant number of PCB traces. Increasing the number of memory controllers may dramatically increase the number of PCB layers (or may not, it really depends on the CPU pinout) but it definitely will increase the number of pins on the CPU socket.
replyThis is one of the main reasons (the other is the number of PCIe lanes) why high end desktop and server CPUs have like double the number of pins and so much bigger sockets as compared to consumer desktop CPUs.
Then what's about using 4-8 cheapest motherboards with 64Gb DDR4 and a cheap CPU, and connecting them via PCIE x16 sockets?
replyAnd as for DRAM channels, typical cheap motherboard has 2 channels and 4 slots, it should not be super difficult to add 2 more channels.
Don't you need a new CPU to support more channels? It doesn't sound like a cheap, trivial change to upgrade my Ryzen to a Threadripper.
replyIn the alternate reality where this happened, wouldn't the price of DDR4 still be sky high? We'll ignore any costs for CPU, chip set, and motherboard redesign. You're just pushing the demand somewhere else.
reply> any costs for CPU, chip set, and motherboard redesign.
replyYes they spent those costs to switch from DDR4 to over-priced DDR5 and I suggested the cost could be spent on adding more DDR4 channels instead.
> just make even cheapest CPUs support 8/16 DDR4 channels
replyIsn't adding pins kind of expensive?
Well to be honest, there are a lot of NOOP pins on CPUs, but using them basically means fabbing a new die altogether, which is basically making a whole new CPU altogether.
replyThis is an odd comment. Pins are seriously expensive. Companies don't just throw them in for fun. Usually they're necessary for signal integrity or packaging constraints.
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