Review of ASRock Rack E3C242D4U2-2T motherboard for budget office server

We love powerful 48-core processors, but not every customer is willing to pay for such capacity: even among modern companies with hybrid infrastructure (local + remote cloud), many are ready to get by with 4-6 core servers based on Xeon E-2100 processors/2200 entry level. In practice, when you need a solution for a host running a security gateway, a 1C server and a Kubernetes node, you can even abandon the use of ECC memory in favor of desktop Core i5, Core i3 and even Pentium Gold processors. In general, where a high frequency is needed in single-threaded loads, there is often only a lack of a normal motherboard, and here it is in front of you.

ASRock Rack E3C242D4U2-2T

Modern server board ASRock Rack E3C242D4U2-2T on the Intel C242 chipset for such extremely cheap assemblies. Although, why cheap, because on the same platform you can build both a NAS with a cold Celeron with passive cooling and a full-fledged virtualization host with a 6-core CPU. For large companies, this is an opportunity to have one motherboard nomenclature for a whole fleet of servers, which means reducing the cost of spare parts. Well, if the customer suddenly asks the question: "Is the server motherboard for Core i3 much different from the gaming motherboard", then do not forget that in addition to the absence of RGB backlighting, server motherboards have:

  • Location of memory slots along the purge of rack cases
  • ECC memory support + ECC modules in the compatibility list
  • Integrated IPMI 2.0 ASpeed ​​2500 controller with dedicated port
  • WatchDog BIOS Support
  • And guaranteed compatibility with Windows Server, RHEL, SLES and Ubuntu Server

Oh yes, I almost forgot: specifically ASRock Rack E3C242D4U2-2T still has the best 10 Gigabit Intel X550-T2 network controller with RJ45 copper ports to date (read our article on differences 10GBase-T versus SFP + for a 10 Gigabit network). That is, you have a completely modern platform ready to become the building block of your hyperconverged infrastructure.

Memory subsystem

The Coffee Lake-S platform has a 2-channel memory controller, and the maximum memory frequency is limited to 2666 MHz. You can only use unbuffered memory with or without ECC support, totaling 128GB. Register memory is not supported.

Memory subsystem

In the QVL list, the main place is reserved for 6 types of 8-gigabyte modules, which is not surprising, but there are two 32-gigabyte ECCs from Samsung and even one 4-gigabyte Kingston KVR21N15S8/4 worth $ 15 for very cheap assemblies, for example, for FreeBSD.

Network subsystem

The pearl of the motherboard is the 20 gigabit pure copper speed provided by the Intel X550-T2 controller. The network controller supports PXE and the first LAN port is NCSI. In the arsenal of ASRockrack there are analogs of this motherboard with a 1 Gigabit network on the Intel i350 chip. As a rule, cards with this controller have iSCSI boot, which is completely absent in 10 Gigabit versions. We recommend you our comparative testing this motherboard.

In addition, for each of the 10 Gigabit ports in out-of-band mode, you can access the motherboard's IPMI interface if there are no free ports for IPMI in the rack.

Interestingly, the rather sluggish Intel X550-T2 network controller has a very large heatsink. This is due to the fact that it is located in the same heat flow with the processor and its VRM module. That is, the network here is cooled with warmer air than, for example, in the board ASRockRack EPYC3251-2T ​​. Why is this done? The fact is that budget 1U cases often have two 40 mm fans in the center of the motherboard, and their flow, though strong, is narrow, so ASRock Rack adapts to such options.

Storage subsystem

There are 6 SATA600 ports on the motherboard, including a SATA DOM with power to the flash drive. This port shares a common interface with M.2 SATA3, so when this module is installed, the port is disabled. Fortunately, this does not apply to M.2 NVME drives, which can be up to 2280 in size and have a PCIE3.0 (X4) interface.

ASRock has a variation of this motherboard E3C246D4U2-2L2T, which has 8 SATA ports and is more suitable for storage, and our ward, in general, is no different in terms of data storage. Yes, there is software RAID 0/1/5 on which you can install Windows, but this is not relevant today.

Expansion slots

Intel Coffee Lake-S platform only supports PCI 3.0, and this is, frankly, the weak side of the motherboard in question. There are three slots on the board in different constructs, from top to bottom:

Asrock Rack E3C242D4

  • Slot7: PCIE-1x from South Bridge
  • Slot6: PCIE-16x from processor (shares 8x/8x speed with Slot4)
  • Slot4: PCIE-8x from processor (shares 8x/8x speed with Slot6)

The presence of an integrated 10 Gigabit controller, of course, helps to do without expansion cards altogether, but if you just need additional controllers, look for the E3C246D4U2-2L2T board, which additionally has a PCIE-4X slot opposite M.2.

Power system

The list of compatible processors includes models with a TDP of up to 95 W, but of course the bulk of the options cost the 40-50 W range, so an 8-phase VRM scheme will be enough. A common 2-phase VRM is used to power the memory slots, while the Intel X550-T2 uses a 3-phase power scheme.

Rear view

Solid capacitors are used for filtration, which, although it looks like an outdated technology, at the same time has high reliability and a service life of about 15 years.

IPMI and BIOS remote management

For remote management, an ASPeed AST2500 chip is used with a dedicated 1 Gigabit network port, which is used only for BMC functions and nothing else. I would like to say that AST2500 is the best solution for today, having a modern HTML-5 interface, optimized for tablets and smartphones. You have access to fast and convenient console management, connecting a remote disk for installing the operating system both from a computer and via a NAS. There is a very convenient temperature monitoring and the ability to record POST tests.

Compared to Dell iDRAC, HPE iLO and Lenovo XClarity management systems, here you don't pay for remote management, but get practically the same capabilities, not to mention the fact that you can simply forget about IP-KVM like a bad dream ... Yes, and one more thing: if you do not use a dedicated gigabit network port, you can access the BMC through a 10-gigabit port: the board implements a kind of network switch, so we can access the web interface of the hypervisor via one network wire, and in the BIOS via the console. Cool!

Of the interesting features of the AMI BIOS, it should be noted that the Watch Dog timer cannot be switched off, which has 2 server reboot modes: Reset and NMI. Also for Xeon processors, enabling hardware application encryption (SGX) and configuring Turbo Boost is available.

Operating system compatibility

While the official list of supported operating systems is frustratingly lacking in VMware ESXi, this is the first operating system I've installed to make sure everything works.

ASRock Rack OS Compatibility

VMWare ESXi 6.7 U3


Ubuntu Linux19.10


Microsoft Windows Server 2019


PFSense 2.4.4 p3


FreeNAS 11.3


Thus, if vSphere is part of your infrastructure, along with FreeBSD, Windows Server and Linux, you can use this board.

Ordering Guide

The motherboard in question will ideally fit into some local office and in a data center in such a case as.

In general, there are plenty of similar motherboards on the market, and so that ASRock Rack E3C242D4U2-2T is not sold to you when buying through a tender, specify in the technical requirements three PCI Express slots (16x + 8x + 1x) and a 10-Gigabit network card with two ports. By doing this, you will discard the entire range of Supermicro X11SSH series boards, and companies such as Tyan and Gigabyte do not have MicroATX solutions on Socket 1151 with an integrated 10 Gigabit network adapter at all.

In general, given that this motherboard has no direct competitors, this is an excellent solution for a budget hyper-converged server.

Mikhail Degtyarev (aka LIKE OFF)

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