Tuesday, July 28, 2009

By Request: a Look Inside the Intel D945GSEJT Server

I received a request today to snap a picture of the D945GSEJT board mounted inside the mini-ITX case, so here it is:

In the picture above, I have marked some of the connectors (and left some out, e.g. the USB ports):
  1. Ethernet port
  2. DVI connector
  3. 12VDC power connector
  4. SODIMM connector
  5. Power switch
  6. SATA connectors
  7. On-board power connector for hard drives
The lower third of the machine as shown in the picture is occupied by the mini-ITX PSU, which I do not use. Because of the design of the case, with the hard drives attached to the lid of the case (the lid is flipped on its side in the picture), there is no room for a PCI card. It would be possible to have a PCI card though, if the machine only needs one hard drive. In that case, the PCI card would be attached to a PCI riser attached to the PCI slot on the board.


  1. I'm glad I found your blog--I planning on building almost exactly the same setup. I see that you are powering the two hard drives using the onboard power connector. According to the motherboard specification the power connector is only rated for up to 1.5A at 12V. The specifications for WD Caviar Green WD10EADS is that they draw a maximum of 1.671A at 12V each, so you are potentially putting more than double the maximum rated load on the power connector. Have you had any problems booting your system? The maximum power draw should be when the drives are spinning up.

  2. Thanks for the feedback! That is an interesting observation indeed. It's a good thing I didn't know that before building the system ;-). Jokes aside, I've never had any problems with the hard drives, except for the problem with a sector that was bad on delivery, which I described in one of my posts.

    1.671A at 12V would make about 20W, which has to be a very extreme case for the WD Caviar Green. I read a review today on a system with D945GSEJT with a 1TB WD Caviar Green and an IDE flash drive. Measured before the AC-DC block, graded at 80% efficiency, the system was idling at 20W with only the flash drive, and at 23W with the WD drive in addition. At full load, the reviewer registered 25-28W with the full setup. In that case, the on board power connector would actually be able to supply two WD drives and still staying withing the limit of 1.5A (18W).

    I'll sum this up in a blog post tomorrow, since I think it's very valuable information. Let me know how things work out for you, and good luck with the build!

  3. Anonymous11:51 PM

    With regards to power consumption of the drives, startup current could be an issue. Motors generally consume more power when they're first started. WD don't seem to specify startup current, but for a Seagate LP drive the value specified is 2.0 amps. I guess that's off the 12V rail. Assuming the Seagate LP has similar characteristics to the WD Green that means you could potentially have a 4A startup current going through that connector and circuitry.

    WD have just released (or announced?) capacities up to 1TB in the 2.5" Blue line - probably a better match for a system like this, although you're going to be paying something like a +100% premium for 2.5" drives...

  4. Thanks for your comment. I'll keep those WD Blue drives in mind. As I concluded in a more recent post (http://jonashagmar.blogspot.com/2009/07/word-of-caution-when-connecting.html), I haven't had any problems with the setup, neither when starting up or when running. It's definitely something to watch out for, though.

  5. Anonymous2:47 AM

    Thank you for the picture. In the meantime I've built a similar PC with D945GSEJT. Could you test if the DVI output works? I couldn't make it work on mine at all. No BIOS screen, no picture in Win7 RC either. No big loss, though, I used the normal VGA plug.

  6. Congratulations on your new system! I started out using the VGA port, and then switched to DVI, without any problems using either one of them. I first thought your problem might be a BIOS setting issue, but as far as I remember, the display output in BIOS is set to DVI+VGA, without any way of changing it. Assuming that is really the case, it unfortunately sounds like you got a defective board.

  7. Anonymous1:02 AM

    I've investigated the DVI issue. The DVI interface only supports 1600x1200, and my monitor "wants" 1920x1080, that's why it didn't work. On another monitor with native resolution of 1680x1050, DVI works OK.

    My System is:
    D945GSEJT, 2 GB Kingston RAM, 500 GB WD Blue 2.5" HDD, one extra network card, one 8 cm fan controlled by the MB. It eats 17-19 Watts measured on the 230 Volt side.

  8. That's good to know, thanks! I have my D945GSEJT hooked up to my Full HD TV with a DVI-HDMI cable and that has worked just fine, but I guess then that my TV is better at adjusting the resolution than your monitor. The only problem is that that the picture is overcropped, at least in text mode (haven't tried any GUI). In my case it doesn't matter though, since I only need the screen to enter the password to the encrypted LVM at boot. The rest of the time, I use SSH to administer the system.

  9. Anonymous8:35 PM

    What is the model of the Mini-ITX case that you have used ?

  10. I used the Emko EM-153 case, see one of the previous posts (http://jonashagmar.blogspot.com/2009/06/i-previously-blogged-about-qnap-turbo.html).

  11. Jonas, thanks so much for sharing your project. I too am looking to build a linux based nas with raid-1 around a mini-itx enclosure, but I cannot seem to find the one you chose (EM-153) here in the US. Were there any others you looked at before going with the em-153 that would accomodate two fullsize 3.5" drives?

  12. Thank you for reading the blog, John. Enclosures accommodating two 3.5" drives, preferably without internal power supplies, are strangely hard to come by. A quick scan of a price comparison site reveals that the situation has not improved since I assembled my D945GSEJT server. My suggestions would be the Chenbro ES30068 or ES34069, or the Morex Cubid 6600 or 6610, but they all unfortunately have internal power supplies, and so taking up unnecessary space. I bought my case from http://www.mini-pc.se. They are very eager to help their customers, and I am sure that if they cannot send you the case themselves, they know of someone who can. The email address is info@mini-pc.se.

  13. Anonymous5:52 AM

    Hello, do the two 3,5" HDD spin up at the same time when starting the server
    or do they spin up one after the other?
    Best regards from Germany ;)

  14. To the best of my knowledge, the disks spin up at the same time, and I have experienced no problems with the set up.