Asus F2A55-M LE

oven1 - open air data processing rig


  • box: foldable plastic storage box
  • power supply: Corsair RM750 modular
  • motherboard: Asus F2A55-M LE µATX
  • memory: 8 GB - 8 GB Kit (2 x 4 GB) DDR3 1600 Mhz CL8, Ballistix from Crucial, was: 4 GB - 2 x 2 GB Corsair XMS3 (TW3X4G1333C9a) (max is 32 GB)
  • cpu: AMD A4-4000 @ 3.2 GHz
  • cpu cooler: stock
  • hard drives: none
  • os storage: usb memory stick
  • GPU: 3 x Radeon HD7870 (Sapphire Radeon HD7870 GHz Edition, 2 GB, PCI-E DVI/HDMI/DP). SN: A133400024711, A133400024713, A133400024715

uefi: 6602 x64, date: 05/22/2014 (was: 6402 x64, date: 07/22/2013) (was: 5107 x64, date: 10/22/2012)

OS: FreeBSD, Xubuntu,

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CryptoBadger - build your own litecoin mining rig, part 1 hardware, part 2 Linux setup, part 4 optimization, Corsair - Connecting an RM Series PSU to Corsair Link,

local links


History / work log

2021-08-16: I re-created this page on my self-hosted web server.

2021-02-14: m3a ucc - I unscrewed this motherboard from its case, and set it up as my new open air rig. Tested with the Radeon HD7870 serial number A133400024711 in the PCIe x16 slot, it powers up and I get a picture. Connected up the R9 280 via the PCI x16 to x1 riser, and that one works as well.

2021-02-10: rs480m2 - I connected the Sapphire Radeon HD7870, serial number A133400024711, monitor connected via DVI-to-VGA adapter. This is a previously "known bad" card. The fans spin up, then throttle down. I get a picture, and the card shows up in pciconf -lv output in FreeBSD. Interesting.

2021-02-10: rs480m2 - I connected the Sapphire Radeon HD7870, serial number A133400024715, monitor connected via DVI-to-VGA adapter. One fan spin up, the other doesn't (but spins a few turns when powered off). No picture. This is the unlucky card that got connected to the PCI slot due to user error.

2021-02-10: rs480m2 - I connected the Sapphire Radeon HD7870, serial number A133400024713, monitor connected via DVI-to-VGA adapter. The fans spin up, but I get no picture.

2021-02-10: rs480m2 - I connected the Sapphire R9 280 card to the motherboard and psu, and connected the monitor to it with a DVI-to-VGA adapter, and the card works, it shows display and it shows up in pciconf -lv output in FreeBSD.

2021-02-10: rs480m2 - I connected this motherboard to the RM750 psu, monitor and a keyboard, and it came right up when powered on. So the psu works. Also booted from FreeBSD install usb stick - everything looks ok.

2021-02-07: connected a PCIe 1X-16x adapter wrong (forced it into a PCI slot, stupid), and now there is no -5V on the RM750 (but modern ATX doesn't have that, anyway). Not sure if the motherboard and / or the HD7870 connected to the 1X-16X adapter is fried to. The 5V stby LED still lights up, but the motherboard doesn't power on. I wonder if I can repair the RM750? I should test it with another motherboard, to see if it is ok.

2016-01-07: bios - newest bios is version 6604 - improve system stability.

2015-01-03: bios - newest bios is version 6603 - improve system stability.

2015-01-03: I picked up the package from Dustinhome today, at my local PIB (Rimi Trondheimsveien). The bridge cable comes in a small antistatic bag, the cable is short, it has an internal usb plug on one end, and two cables on the other end, one with a two-pin plug, and one with a three-pin plug. My RM750 psu came with the matching cable, it is 82 cm long, have the two- and three-pin connectors at one end, and a four-pin connector at the other end labeled "Type 3". This four-pin connector looks like it will fit in the C-Link plug on the RM750. To test this without mounting it internally, I can use a EXUSBIE-40 or similar.

2014-12-29: While buying other stuff on sale at, I filled up my order with a Corsair Link Analog to Digital Bridge Cable (5010756040) for NOK 235.- to get free shipping (orders over NOK 3000.-).

2014-07-08: bios - newest bios is version 6602. Downloaded and put on a usb stick. Installed. I had to remove all GFX cards to access settings again. I set primary video device to IGFX Video and Force. Disabled: HD Audio, Serial and parallel ports.

2014-07-07: I got a delivery text message (and email) from Posten, and picked up the package from NetOnNet at my local PIB (Rimi Trondheimsveien) on my way home this afternoon.

2014-07-04: I got a shipping confirmation from NetOnNet.

2014-06-29: I ordered a Sapphire R9 280 3GB Dual-X GDDR (art nr 201856) from NetOnNet for NOK 1549.- estimated back in stock 2.7.2014.

2014-06-29: GFX card failure - the machine simply will not boot / show anything on screen with the "defective" HD7870 card connected to the PCIe bus. Time to look for a replacement?

2014-06-29: today I took a closer look at the machine. Even without a usb stick in, the machine wouldn't show a BIOS screen or anything on display. I disconnected the GFX card connected to a PCIe 1X slot, and powered the machine on again. This time I get a BIOS display, which says:

"New CPU installed! Please enter Setup to configure your system."
"Press F1 to Run SETUP"

Ok, that's interesting. Into Setup, save and exit. Back out of Setup, every time I connect the PCIe 1X GFX card, nothing happens - no display, no boot. With this GFX card disabled, and the usb stick in, the machine boots.

2014-06-26: maybe it is accidental, but during some thunder and lightning this evening, the machine stopped, and wasn't booting after that. fsck'ing the usb stick didn't help.

2014-04-12: I rebuilt the machine, and while doing so I exchanged the 1X-16X adapter on the third gfx card (the one closest to the PSU) with a 16X-16X adapter (not powered). I also made a better solution for the gfx cards to rest on.

2014-02-09: today I installed the third cgfx card. I used a 1X-16X adapter (powered for the 1X slot, and also for the last 16X slot (since I don't have any 16X-16X adapters yet).

2014-01-19: memory - I replaced the two 2 GB DIMMs with two 4 GB DIMMs taken from the vm machine: 8 GB Kit (2 x 4 GB) DDR3 1600 Mhz CL8, Ballistix from Crucial, so now the machine has 8 GB memory.

2014-01-15: I got a pickup notice for the package with 2 x 4PIN Molex Power Filter PCI-E Extension Cable 1x 16x Extender Riser Card Adapter, and picked it up at my local PIB (RIMI Trondheimsveien). The reason for the pickup notice was that the package was sent as registered mail.

2013-12-31: I got a shipping notice for 2 x 4PIN Molex Power Filter PCI-E Extension Cable 1x 16x Extender Riser Card Adapter, ordered on eBay.

2013-12-26: bios - newest bios available is version 6402. I downloaded that version, put it on a FAT32 formatted USB stick, and used EZ Flash 2 to update. Then I did the settings again (sigh).

2013-12-26: boot - to get the machine to diplay BIOS / UEFI, I took out the HD7870 cards (it was the easiest solution). BIOS version is 5107. In BIOS, Advanced, NB Configuration, I selected IGFX Video as the Primary Video Device. I left Integrated Graphics on Auto. Hopefully, this will give me a display even with the HD7870's in the machine. For Onboard Devices, I disabled HD Audio, Serial port, parallel port.

2013-12-25: install - I installed the APU on the motherboard, the APU cooler (thermal grease was preapplied) and connected the APU fan. memory - I installed 2 x Corsair XMS3 2 GB modules (TW3X4G1333C9A) that I had free. It will give me 4 GB memory. Installed the PSU (Corsair RM750) and connected up the ATX and CPU cables to the motherboard. Bothe the motherboard and the PSU is placed (loose) at the bottom of the plastic box I use as a cabinet. Added a cable to the power switch pins on the front panel connector on the motherboard.

2013-12-23: quite late in the evening (2040 local time) I received a pick up notice from the postal service. Because my local place to get packages is a PIB (RIMI Trondheimsveien), they are open until 2300 on weekdays, so at 2144 I had picked up the package and was back inside in my dry apartment (it was raining outside).

2013-12-20: sent a shipping notice - all items in the order shipped, good.

2013-12-11: from a seller on eBay I ordered 2 x 4PIN Molex Power Filter PCI-E Extension Cable 1x 16x Extender Riser Card Adapter at USD 9.99 and USD 4 in shipping, a total of USD 23.98, not bad.

2013-12-11: From I ordered: 1 x Corsair RM-750 power supply (NOK 912.-), 1 x Asus F2A55-M LE microATX motherboard (NOK 549.-), 1 x AMD X2 A4-4000 APU (NOK 349.-) and 3 x Sapphire Radeon HD7870 GHz Edition 2GB PCI-E gpus (at NOK 1599 each, a total of NOK 4797.- for the GPUs). The total was NOK 6587.-). I will use existing memory (I have some 4 GB DDR3 DIMMs, which should give the machine 8 GB). It turns out they only had one HD7870 in, the two others was backordered, estimated delivery 20.12.2013.

2013-12-11: a thread on one of forums planted the idea in my head that I should try to build an open air rig - for fun. All of the machines I have built so far has focused on low power and no noise, so this will be a change.