Why TR4 mITX don't exist, as LGA 3647 shows

Jurrunio · May 7, 2019

Thought about posting in the news section, but then this is WCCFtech, reputable? I dont think so. Mods please move it if necessary

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WCCFtech's post isn't all that detailed, so not quoting their words.

This is the EPC621D4I-2M from Asrock Rack (no, not those racks). Server board department basically, building this insane piece of engineering to maximize density with LGA 3647 support. It's rated for TDP up to 205W with its 6 phase VRM with super tall (yet not wide) heatsinks and the whiney type of inductors, so Cascade-Lake-SP series will all work properly with the board but not the W-3175X at 255w TDP (likely no turbo boost)

So to put this massive socket into an mITX sized piece of fiberglass, the hexa-channel memory supporting CPUs will have to make do with quad channel SODIMM memory. There's only 1 SATA port (for DOM, disk on module use as this is a server board) on the board itself, relying on the U.2 SFF-8639 to expand into 4 SATA ports or a PCIe 3.0 x4 connection. At the back there are 2 M.2-2280 supporting slots capable of running PCIe x4 and SATA. I/O is ridiculously barren by HEDT standards though normal for a server board, with 2 ethernet ports (not sure if 1 gigabit or 10 gigabit), 2 USB 3.0 (I know officially it's 3.1 Gen 1, but they are functionally the same and I despise the naming scheme) and a VGA display out. There also seems to be 2 PWM fan headers, 1 DC fan header and a front panel header.

TR4 socket (58.5mm x 75.4mm) is ever so slightly bigger than LGA 3647 socket (56.5mm x 76.0mm), so if an mITX board exists for Threadripper it will share all the problems if not more. You could get by with limited storage connectors, quad channel is fine, rear I/O wont be anywhere near enough without expansion hubs (even with VGA port used to build more USB ports, and forget PS/2 support as USB is more important), it can't support 250w 24 core and 32 core Threadrippers at full speed, there wont be any audio codec that would fit on the board so you're relying on the graphics card for audio, and zero RGB on the board itself. Oh, and front panel connection only include power and reset switches as not even USB front panel headers exist. I havent got into the debug features and crash-recovery system yet...

Does that mean TR4 on mITX is silly? Yes, totally yes, you have to be insane and masochistic to buy a board with this many flaws and limitations (most likely a crazy price as well) for yourself, and that is why you should.