Intel i354 quad Ethernet onboard. mATX form factor with two PCIe slots. An open ended x8 slot which allows for adding larger x16 cards. Cool PCIe expansion area optimizes cooling for add-in cards. Stable platform.
Lower onboard device integration opting instead for exposing PCIe lanes to slots
Today we are looking at a very unique solution based on Intel’s low power Avoton SoC: the Supermicro A1SAM-2750F. The platform features a mATX Supermicro motherboard with an embedded Intel Atom C2750 SoC. The SoC is an 8 core design which we have a dedicated performance thread in the forums on. We also published power consumption and Intel Atom C2750 performance numbers using Supermicro platforms. To date, all of the Intel Atom C2000 series platforms we have reviewed have either been in a mITX form factor or in custom form factors for high-density applications. Practically, that limits designs to a maximum of one expansion slot. Supermicro saw the need for a larger form factor with a greater ability to customize and released the A1SAM-2750F to address this market.
Due to the SoC design, the Intel Atom C2750 platform is very compact and requires very little to get up and running. STH has more Intel Atom C2000 reviews live than other sites at this point so we do have quite a bit of experience with the platforms in general. We are keeping this platform as much in-line with previous configurations as we can.
- Motherboard/ CPU: Supermicro A1SAM-2750F with Intel C2750 Avoton 8C/ 8T SoC
- SSD: Intel S3700 100GB SSD
- Memory: 32GB (4x 8GB) 1600MHz 1.35v DDR3 DIMMs, 16GB (4x4GB) 1600MHz 1.35v DDR3 DIMMs by SK.Hynix
- OS: Ubuntu 13.10, CentOS 6.5, Hyper-V Server 2012 R2
- Power supply: 1U 200w 80+ Gold PWS-203-1H
We also utilized our standard array of PCIe add-on cards along with Seagate and Western Digital spindle drives to text maximum configurations, but those were our two main test beds. We only used PCIe x1 and x4 add-in cards with the x4 slot due to physical size limitations.
The Supermicro A1SAM-2750F
Looking at the Supermicro A1SAM-2750F we see a motherboard that is in many ways similar to the Supermicro A1SAi-2750F but that has some stark contrasts. The biggest one is perhaps the physical size at 9.6″ x 7.5″ it is a mATX form factor.
Perhaps the most exciting feature are the two PCIe expansion slots. The Supermicro A1SAM-2750F has both a PCIe 2.0 x8 and x4 slots. One excellent design feature is the PCIe x8 slot is open ended. That means that one can install PCIe x16 physical cards into the motherboard even if they run at x8 electrically. Supermicro also keeps the area behind the PCIe x8 slot clear so there is clearance to fit another card.
In terms of overall layout and airflow, the 20w TDP part requires very little cooling. The DDR3 DIMM slots are aligned with proper front to back server airflow considerations in mind. As we will see in our thermal imaging results, the impact of combining solid airflow and very cool running system components on a motherboard is excellent.
One major feature of the platform is the use of full-length standard DDR3 SODIMMs. In this shot we have SK.Hynix 1.35v DIMMs. In a low power platform such as this one, low voltage memory has a large overall percentage impact on the platform power.
There is also another change from the Supermicro A1SAi-2750F we reviewed previously. There is no 4-pin power connector atop the motherboard. Nor is there a USB 3.0 front panel header. Instead there is a USB 2.0 internal port which is excellent for VMware ESXi boot devices as an example.
Along with the internal USB header, one can see two SATA III ports and four SATA II ports. There is even a SATADOM power connector for embedded applications. These SATA ports emanate from the Intel Atom C2750 onboard.
The rear panel of the A1SAM-2750F also differs from Supermicro’s other offerings in that there are four USB 2.0 ports. This design trade-off is easy to understand as Supermicro used the PCIe lanes from an added USB 3.0 controller to instead drive an extra PCIe slot. Legacy VGA and serial connectors round out the standard I/O functionality
One can also see five RJ-45 ports on the rear of the motherboard. One is a dedicated IPMI network port driven by the ASPEED AST2400 chip seen just above the VGA connector. The other four ports are gigabit Ethernet ports. Supermicro utilized the onboard Intel i354 and a Marvell PHY to provide the platform with quad LAN capabilities. While other vendors have used NICs with lower costs and fewer features, this design choice by Supermicro is excellent. For those wondering, in OSes such as Microsoft Windows, RHEL, CentOS, Ubuntu, Debian, Mint, VMware EXSi, FreeBSD 10 and etc. the NICs appear as Intel i354 NICs. Most operating systems have supported these NICs out of the box since the beginning of 2014.
For our thermal imaging tests we use our new FLIR Ex series thermal imaging camera with FLIR’s new MSX software to show details overlaid on the 320×240 thermal image.
As mentioned earlier, the platform is extremely low power. We managed to get excellent results with all ICs running well below rated temperatures. Furthermore, for those considering adding hot PCIe cards, the A1SAM-2750F’s bottom runs extremely cool.
Software and Management
Supermicro’s IPMI and KVM-over-IP as described a few times on this site, allows for a lot of deployment flexibility. Things such as fan speeds, chassis intrusion sensors, thermal sensors, and etc. can be monitored remotely. Alerts can be setup to notify the admins of issues. Beyond this, the functionality also allows for remote power control. You can do remote power up, power down, and reset of the server in the event that it becomes unresponsive. In fact, the test system has never had a keyboard, mouse, CD/DVD ROM, or monitor hooked up to it, even after multiple BIOS tweaks and operating system/ hypervisor installations.
Another important feature is the ability to remotely mount CD images and floppy images to the machine over the dedicated management Ethernet controller. This keeps maintenance traffic off of the primary Intel NICs. At the same time it removes the need for an optical disk to be connected to the Supermicro motherboard. Combined with the onboard Type-A USB 2.0 header, mounting OS installation or recovery images remotely is a very simple affair.
Overall the trade-off of removing USB 3.0 and increase in size benefit those who want to further customize Intel Atom C2750 platforms. The decision to use the Intel i354 as a great one as it is a relatively high-quality onboard quad port NIC. The ability to utilize industry standard DDR3 UDIMMs in the platform lowers the overall cost of the platform slightly. There are a variety of use cases where the A1SAM-2750F makes a lot of sense including network appliances and cold storage servers. As a result of this innovation, along with the platform’s stability, the A1SAM-2750F receives very high marks in our testing.