One of the objects that makes a motherboard instantly standout is the quantity of reminiscence slots it has. For mainstream platforms, having two or 4 reminiscence slots, for twin channel reminiscence at one DIMM per channel (1 DPC) or two modules per channel (2 DPC) respectively is regular. If we noticed a motherboard with three, it will be slightly odd.
We’ve seen high-end desktop platforms have three (Nehalem) or 4 (virtually all the pieces else) reminiscence channels, so we see both 3/Four or 6/eight reminiscence slots respectively for 1 DPC and a pair of DPC. When transferring into server {hardware}, Intel’s Xeons have six channels, whereas AMD’s EPYC has eight channels, so 6/eight and 12/16 for 1 DPC and a pair of DPC are apparent.
So what occurs when a motherboard shows a unique variety of reminiscence slots than anticipated? This is what occurs with the brand new ASRock Rack ROME6U-2L2T motherboard. It helps AMD EPYC processors, each Naples and Rome, which have eight channel reminiscence. Even at 1 module per channel, we anticipate a minimal of eight reminiscence slots. But for this motherboard, there may be solely six.
This signifies that this motherboard, at greatest, runs in six-channel mode. With a central IO die, like Rome, which means that total reminiscence bandwidth is lowered by 1 / 4 (or a fourth). For Naples, this will get even weirder, as a result of there isn’t any central IO die, and it means one chiplet out of the 4 doesn’t have entry to reminiscence, much like how Naples-based Threadripper methods had two chiplets unable to immediately entry reminiscence.
By why on the earth would a motherboard vendor do one thing like this. It appears counterintuitive, and needlessly hamstrings the processor efficiency, proper?
There are a spread of explanation why this can be a good thought. For a begin, decreasing the general bandwidth (not less than, in a Rome CPU) would solely have an effect on environments and software program setups which are peak reminiscence bandwidth certain. It additionally reduces the price of absolutely populating the system with reminiscence, and it reduces the facility consumption sufficient that maybe various cooling will be thought of.
In the scenario of this ROME6U-2L2T, the opposite issue is dimension. ASRock is placing this large EPYC socket in a micro-ATX kind issue, and with a purpose to benefit from the 128 PCIe 4.zero lanes on the motherboard, wished to place a full x16/x16/x16/x16 structure on the PCIe aspect. In order to do that, the one solution to give sufficient house for the PCIe slots was to cut back the overall quantity of reminiscence slots out there to the CPU. It’s an fascinating tradeoff, probably made on the request of one among ASRock Rack’s clients.
Another angle to contemplate is a buyer with an improve path. If a buyer is transferring from a single socket Xeon platform with six reminiscence channels stuffed at 1 DPC, then upgrading to AMD with a motherboard that solely has six reminiscence slots means the reminiscence can switch over with none further value. This is an outdoor risk, however one nonetheless.
As for the motherboard, it truly comes very properly geared up. Those 4 PCIe slots are certainly all PCIe 4.zero x16, and the board has assist for 14 SATA ports (12 by way of mini-SAS), three U.2 ports apparently able to PCIe 4.zero x8 assist, twin 10 gigabit Ethernet ports (10GBase-T by way of Intel X710-AT2), and two common gigabit Ethernet ports from Intel i210-AT controllers. Onboard BMC is offered by an ASPEED AST2500, which additionally has a D-sub 2D video output and a devoted community interface.
There are additionally six four-pin fan headers, which is quite a bit for a board this dimension (though they’re all within the high proper nook), in addition to a TPM header, a COM header, a USB 3.zero header, a USB 2.zero header, and USB 3.2 Gen1 ports on the rear.
For motherboards with irregular configurations, this ROME6U-2L2T isn’t the primary. Here’s a glance again by way of just a few that I bear in mind.
The GIGABYTE EX58-UD3R…
