[sclug] Multicore motherboards of choice

Will Dickson wrd at glaurung.demon.co.uk
Tue Mar 18 19:49:02 UTC 2008

M.Blackmore wrote:
> Guidance for the perplexed gladly received!
> On Sun, 2008-03-16 at 17:06 +0000, Tom Carbert-Allen wrote:
>> AMD Quad core Phenom ?118
>> 2gb ram approx ?25
>> 19" tft ?99
>> nvidia 8500 ?45
>> motherboard approx ?30
>> case and decent psu ?40
>> 250gb hdd ?33
>> dvd-rw ?15
> ==========

I'm woefully out of touch myself, so take the below with a pinch of salt.

> Power supply units - do these new motherboards use the older atx psu's
> as I seem to recall an extra 2 or 4 pins have been added to the block in
> recent years...? 24?? 

Yeah, they keep changing the spec, mostly to keep up with the insane 
power requirements of modern CPUs and GPUs! Last I've seen it was "ATX 
2.0" which AIUI is roughly equivalent to "ATX12V". (I think it's now
up to ATX 2.2.)

Generally you'll get a 24-pin main plug on the PSU, but either the PSU 
or the mobo should come with a suitable adaptor if the PSU and mobo 

Additionally there will probably a separate 4-way plug from the PSU. 
Look for a matching socket on the mobo and plug it in if it exists, but 
if it doesn't then don't worry.

> totally out of touch with what constitutes up to date technology, ram
> standards, slots (new video slot standard isn't there nowadays, pci/e or
> something to replace agp) and so forth.

PCI-E (PCI-Express) is supposed to replace both AGP and PCI. However, 
apart from graphics cards, most add-on cards are still PCI, so all sane 
mobos have PCI slots as well as PCI-E. (They aren't compatible with each 
other at all).

To add to the fun, PCI-E 1.1 came out a while ago, and PCI-E 2.0 came 
out recently; it's twice as fast as PCI-E 1.0 or PCI-E 1.1. PCI-2.0 
cards (such as the nVidia 8800GT I recently tried to buy) *are* 
backward-compatible with PCI-E 1.1 mobos (although they may not work at 
full speed). However (as I found out the hard way), they aren't 
compatible with PCI-E 1.0 mobos, such as the one in my machine. The 
supplier was very understanding. :-/

> As we've got masses of cases and old atx psu's 

Probably not good enough. It sounds like you're building a Real 
Computer. Those need Real PSUs; I'd advise at least 450W, and I'd spend 
a bit extra to get a good one rather than a bare-minimum white-box job. 
El-cheapo PSUs do not tend to last very long these days.

> 2. Ram - I'd go for 3 or 4gb for future proofing a bit, we have a lot of
> windows open habitually and use up the ram quite a bit. 

4GB is pointless unless you've got a 64-bit-clean OS / software stack - 
the last 1GB of the 32-bit address space is reserved for memory-mapped 
I/O of various kinds, so the last GB of RAM won't be used. I'm still 
running on 1GB, which was above average when I built this box but - 
thanks mostly to Vistugh - is now passe. Personally I wouldn't bother 
with more than 2GB unless you have reason to suppose that you'll really 
need it (or you're rich :-). More kit needs more cooling, which creates 
more noise.

So whats the ram
> of choice at the moment (what ram standards are there)?

I think DDR2 is the weapon of choice ATM. Your CPU will dictate your 
mobo, which in turn will dictate your RAM technology. Check the mobo 
manual / specs.

> 3. Good video card - we're beginning to do some video editing from the
> camera, my daughter is into this a bit, and finding all our kit wheezes
> desperately with Gimp and err wotsit for digital video editing. What is
> the trade off - amount of video ram or raw speed of the gpu for digital
> camera film editing? 

TBH I don't think it'll make that much difference. Right now, GPU 
horsepower generally only comes into play for either 
hardware-accelerated decoding of HD-video, or 3D gaming. That said, 
there are up-and-coming initiatives such as CUDA which aim to change 
that; if you think you might be interested in that (and from what you 
said, it sounds as if you might be, in due course), getting a 
CUDA-compatible GPU might be a plan. CUDA is an nVidia initiative; I 
suspect ATI / AMD have an equivalent. I've tended to be an nVidia fan 
because IME their linux driver blobs actually work, but ATI / AMD are 
currently ahead in FOSS support so they might well be catching up.

> 4. Do we need a new psu? 

Almost certainly; see above.

Energy efficiency wise it might not be a bad
> idea to get stuff with power factors of greater than .85, nothing I've
> tested thus far with a power meter has broken more than .59 which is
> dreadful efficiency on a digital electricity meter where we get charged
> for stuff out of phase on the neutral line :-(

Switching PSUs are inherently a nasty load. In fact, they're often close 
to being negative resistance! This sounds like another good reason to 
invest in a high-quality PSU.

> Where's the best sort of place to source this as an end user 

I've been using http://www.cclonline.com/ recently, and I'd recommend 
them - eg. they took back the PCI-E 2.0 card I mentioned above without 
trying to charge me P&P or restocking fees. Their prices seem to be 
competitive, although they don't tend to stock higher-end gamer / 
enthusiast parts. It can still pay to shop around.

> Having lost touch, how does one "get back in knowledge" ... I'd been
> organically part of microcomputing since the late 70s until 2002 or so,
> so never noticed that I always knew what was hot and what was not, but
> now having become outdated I realise I don't have a clue how one, err,
> clues oneself up from scratch like a newbie??

Google remains your friend :-).

Some places I've found helpful:
- tomshardware.com / .co.uk
- anandtech.com
- hardocp.com

A final point (and see threads passim): if you're just looking for a 
reasonable box on the cheap, rather than wanting the whole DIY 
experience, it's probably an idea to check the price of a complete box 
from the likes of Dull even though you do have plenty of spare parts. It 
might well be cheaper to buy a complete base unit ready-made, than to 
buy half a computer in components to go with the half a computer you 
already have to hand. Strange but true.

Best of luck,


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