Low-cost number-cruncher

[DerbyJon]

I'm looking to build a cheap but quick linux PC. This will be used for running my own command-line based software. No desire for high-end sound or graphics, just plenty of grunt for wading through lots of floating point calculations.

I've decided on Intel, as AMD seems to be at least double the price for the performance level I'm looking at. I was initially opting for a low end Pentium D (930) with a Core 2 Duo capable motherboard to give the option of an upgrade later. However, the Allendale E6300 is only around £10 more expensive and seems to be comparable in performance to a low-end AMD FX-60.

As regards the mobo, the Intel DP965LT would do the job for less than £90. But what about the Asus P5LD2-VM SE? This is showing up around the £60 mark but doesn't seem to be available until the end of July. Anyone know much about it? It seems to also have integrated graphics which would be good enough for my needs and would save another £20 or so.

Finally, and admittedly this is not the most appropriate forum to ask this, will I need to write my code using multiple threads to get the most out of the dual cores?

[kalniel]

I'd actually recommend getting a D805 from intel - bargain price and fantastic overclocking if you just want number crunching.

Depends on what your code is doing. If you can lever SMP within the same program then yes you'll need to write your code specifically. However the simplest way to get the most out of dual core is to write your code so that you can run more than one executable at a time, or so that you can fork/child the process - ie split your data where possible and have each core running at the same time on half the data. It's usually quite simple, you just have to keep an eye on shared resources.

[DerbyJon]

I did consider an over-clocked D805, but wondered how much of the £55 price saving would be eaten up cooling the thing down?

[kalniel]

I don't think you really need extra cooling unless you are going for extremes. As long as you have a case with good airflow (I use a centurion 5 - very cheap) you should be fine -the lack of GPU will save you both from extra heat and power draw.

[DerbyJon]

Hmm. I'm intending to use a cheap ebuyer case for £15 which undoubtedly includes the ability to strip skin during panel removal. A centurion 5 is probably £20 more than this.

On another point, based on past processor launches, when would you expect to start seeing a little more choice on the motherboard front?

[kalniel]

For new/next gen processors? August will see the ramp up of more AM2 and conro^H^H^H^H^H Core2 Duo boards, then it tends to be a fairly steady trickle.

[alsenior]

do what im doing and build a low cost cluster

[DerbyJon]

do what im doing and build a low cost cluster

Sounds interesting. What are the details? I assume you lose a fair bit in overhead though (extra cases, PSUs, motherboards).

[alsenior]

ill be putting the thread up tommorow.
i really wont need extra cases just power supplies
hte motherboards i picked up in an auction for £21 with cpu's
all i need are psu's and a switch if i need anymore bandwidth on the interconnect i can use an extra nic plus i get areoiund 7ghz raw processing power. cheaper and faster than the pentium 805 solution and the power increase is neglegable
plus linux is perfect for this type of thing.

[Steve B]

id not recommend a cheap ebuyer case, as ebuyer seem to have a habit of taking out all the 1-star ratings to make the average rating higher. I posted a very bad rating, along with a more detailed explanation of the problems with the case, such as pieces spontaneously breaking off, razor-sharp edges on the half-millimeter aluminium sheeting, it didnt have any mounting screws, just punched out n shapes for screwing mobo into, which shorted the ethernet and sound chips, and broke one of my motherboards. also, i farted on it and it collapsed.

Rant over, pick up an old solid steel case from a charity shop or something. Cheaper, and much more sturdy!

[Rack]

But for size, an 805 is much more realistic. It'll run comparitively hot, but the stock cooler works fine, as long as you have OK ventilation. I wouldn't overclock it without good ventilation.

[DerbyJon]

ill be putting the thread up tommorow.
i really wont need extra cases just power supplies
hte motherboards i picked up in an auction for £21 with cpu's
all i need are psu's and a switch if i need anymore bandwidth on the interconnect i can use an extra nic plus i get areoiund 7ghz raw processing power. cheaper and faster than the pentium 805 solution and the power increase is neglegable
plus linux is perfect for this type of thing.

Look forward to the thread. How do you go about using the cluster? Does your software need to be written to be aware of the topology? Is it a matter of sharing partial results by moving files around or something more involved?

[DerbyJon]

id not recommend a cheap ebuyer case, as ebuyer seem to have a habit of taking out all the 1-star ratings to make the average rating higher. I posted a very bad rating, along with a more detailed explanation of the problems with the case, such as pieces spontaneously breaking off, razor-sharp edges on the half-millimeter aluminium sheeting, it didnt have any mounting screws, just punched out n shapes for screwing mobo into, which shorted the ethernet and sound chips, and broke one of my motherboards. also, i farted on it and it collapsed.

Rant over, pick up an old solid steel case from a charity shop or something. Cheaper, and much more sturdy!

I get the impression you weren't entirely bowled over by the case. Maybe this would be the rare occasion I'd be better off on ebay? I have one spare case, but that is a circa 1991 full tower, weighs half a ton and would need the assistance of a hacksaw and drill to be any use.

[DerbyJon]

But for size, an 805 is much more realistic. It'll run comparitively hot, but the stock cooler works fine, as long as you have OK ventilation. I wouldn't overclock it without good ventilation.

I was already pretty nailed on for the low-end core2duo. Having read today's review on Hexus, there's no way I'm going to use anything else. The only doubt now is whether to stick with the E6300 or be tempted up to the E6400 for only £10 more than I'd budgeted.

[alsenior]

Look forward to the thread. How do you go about using the cluster? Does your software need to be written to be aware of the topology? Is it a matter of sharing partial results by moving files around or something more involved?

there are two ways you can build a cluster in a software sense. you can build it with mpich or with the modified openmosix kernel. mine will be based on openmosix. the only thing open mosix need is that it can only run if the application doen not use pthreads of has shared memory between threads a shot list is avalable here

works
doesnt work

yopu can use mpich but that is more complex to set up where as openmosix is alot easier

[DerbyJon]

there are two ways you can build a cluster in a software sense. you can build it with mpich or with the modified openmosix kernel. mine will be based on openmosix. the only thing open mosix need is that it can only run if the application doen not use pthreads of has shared memory between threads a shot list is avalable here

works
doesnt work

yopu can use mpich but that is more complex to set up where as openmosix is alot easier

Crikey. That's pretty useful. Couple of questions. Has openmosix found its way into standard linux distros yet? (I was intending to use Suse 10.1 but am easily persuaded). Also, how do you think it would cope with a cluster of multi-core systems? You need to code multi-threaded to get the best out of the multi-core environment, but wouldn't this prevent openmosix from propogating the work around the rest of the cluster?