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Mother*****!

I finally got around to sorting out my Linux server upgrade.


Case modifications


Started out by cutting a big hole in the back of my main Linux server's AT case for the ATX motherboard's backplane so the keyboard, mouse, etc can actually be plugged in.

The case could really do with a bit of extra material adding to it... motherboards don't fit flush to the case, there's about a half inch gap between the edge of the motherboard and the case... the expansion slots have a section of the case that is set into the case by that amount that the bracket of the card fits onto. In an ATX case, this set-in also includes a hole for the backplane to fit into.

Old AT cases don't have the backplane portion of this set-in; AT motherboards only have a single external connector on the motherboard, a 5 pin din socket for the keyboard, so the cases just have a hole that the plug goes through... So at the moment, I've got a couple of M3 bolts acting as spacers/fixers at the end of the backplane away from the expansion slots to stop it slopping around or coming free). To propely finish the job, I'd like to make up a new bit of case that the backplane will fit into... I'd like to atleast have a piece of material that acts like extrusion of the hole in the case-proper; this would only need a strip of metal of the right width that I could ben in the relevent places. I'd probably need to get hold of a gas torch to heat the metal in order to make nice neat corners in the strip... a few little right-angle brackets bolted to the strip will act as the case fixings.

But for now, that's a "would be nice" not a "this needs to be done" thing...

Also needed to put a few new fixing holes for the mobo... AT motherboards don't drop in the same relative position as ATX ones and there don't seem to be many of the original AT fixing points that have carried over to the ATX standard. This means that there is a two inch strip of motherboard that is floating in free space inside the case, but that it doesn't really matter too much as I've got a decent number of little plastic stands under the board along the edge of the case material. In some ways it's probably better than it would be if the metal sheet under the motherboard extended that extra few inches; means there is better airflow to the underside of the CPU socket and plate, which should (atleast I think it should) improve CPU cooling a little.

And finally I've put a plate (well, a chunk of the top off an old and dead DVD-ROM drive) over the hole that I've had a second AT PSU in for ages... my new 650W ATX PSU delivers more wattage than the two AT PSUs that I've had powering the box combined...!

So I now have the essential case modifications done and have gained back a reasonably large amount of case real-estate. With a bit of work, I'll be able to mount a few more HDDs in there if I want/need to.





Problems


Having gotten all the 'engineering' stuff done, the assembly went nicely and none of the components are dead, but that doesn't mean things have gone smoothly... not a chance!!!

It all comes down to the damned motherboard...! The stupid MSI motherboard I bought for my Linux/Opteron box turns out to *SUK* with Linux... I'm *sure* I did the research thing to check the compatibility... obviously I can't have done a very good job of it... (or there wasn't any info back then...)

Anyway... turns out that there are problems with SATA and USB with my board... and Linux won't enable either of them :-(

Having tried the few 'fixes' people have mentioned, with no success, I've bitten the bullet and bought another motherboard of eBay yesterday...





Stop-Gap Solution


The problem I've got is that I have a Socket-939 processor... and AMD killed off Socket-939, so the choice of boards is limited to whatever is on eBay when you look.

Anyway, the new will be an ASUS A8V-E Deluxe NW, with a VIA K8T890 chipset.

This one doesn't seem to have any Linux-specific issues that I've come across on Google, and it actually has Linux drivers on the ASUS and the VIA websites!

The only thing I haven't been able to absolutely ascertain is the driver for the SATA... there is a VIA SATA driver, but its for a 6xxx chipset, which the A8V-E Deluxe isn't, it's newer... www.linux-ata.org says that VIA are known to have used AHCI in newer chipsets, so I'm hoping its one of those.

There IS a major MAJOR problem with the VIA K8T890 chipset; it doesn't(atleast didn't when new) support dual-core AMD chips... the ASUS site doesn't list any dual-core ships against this board's processor support, and since my chip is dual core, this is obviously not good... I'm making an assumption at the moment that the chip will run as single core (I don't think that that is too big a guess to make as to what will happen... seems logical atleast!). The latest BIOS revision is 1012 (dated on the website as 2nd March 2006) which is the one that the supported-chip matrix is based on.

Other VIA chipsets don't have the problem... :-(

ABIT has dual-core Athlon X2 CPUs listed against their K8T890-based AX8 v2.0 mobo, and this article, from March 2005, (slightly ambyguously) says that VIA "have fixed this with the latest chipset silicon which is going to be available and shipping [...] shortly".

So that may mean that VIA fixed it in a revised version of the K8T890 chipset, or it may mean that other chipsets don't have the problem.

So this motherboard is (at the moment atleast), something I'm looking on as a stop-gap solution. Its only cost my about 35 quid, so it's not too financially annoying to do it this way.

I'm planning to monitor eBay for a 'nicer' mobo; I don't want AGP on the board, I'd like a few additional PCI-E slots above and beyond one for the graphics card, I need a few PCI slots and I'd like to get atleast 4 SATA connections as well (the ASUS board only has 2).

I'd also like the board to come from a manufacturer I've got a clue about - there are quite a few Socket-939 boards on eBay from board-bods that I don't really know.

If the board turns out to run the chip as dual-core, then I might change the plan, but the number of SATA connections may persuade me otherwise... or I might look to but Ultra2 SCSI drives instead of SATA for any future expansion.





For the moment, the system is up and running the old K6-oriented i586 installation of Linux... I can't be reinstall the box until I've got a board that has working SATA so I can juggle the data around to the new SATA drives.

The only tweak I'm considering is to install an SMP kernel that will mean I can tell whether the two cores are actually being used by the chipset. Other than that, for now atleast, I'm leaving the installation as-is.

Comments

( 1 Morsel — Spin A Cobweb )
mr_self_destruc
14th Sep, 2006 08:26 (UTC)
I miss you.
( 1 Morsel — Spin A Cobweb )