How much memory for a barebones cruncher?

magman · 13 Aug 2007 at 18:18

I'm working on the specifications for some new barebones crunchers and I'm not sure what the optimum memory should be for them, so I thought I'd ask some advice from my teammates.

I'm currently looking at a Intel Q6600 in a Gigabyte MATX board that I'm planning to remote-boot into Linux, probably Ubuntu using LTSP, and run the Linux Native SMP client. What I'm trying to figure out is whether to spec. 1 Gig or 2 Gig of memory for the cruncher, is it worth spending the extra money to go for 2 Gig, or will 1 Gig be sufficient?

This gets a bit more significant when you consider that I might be buying 4 of these babies. It might be the difference between upgrading one of my other crunchers or not (E6300 to Q6600).

SiriusB · 13 Aug 2007 at 18:25

If you only plan on running one or two SMP clients then you might get away with 1GB. However, given how cheap memory is I'd be tempted to go with 2GB.

Mattus · 13 Aug 2007 at 19:03

You'd get away with 1GB as they're dedicated crunchers. You want to be running two instances on each. Each instance of LinSMP will use about 300MB, 350 max, leaving you at least 300MB for Ubuntu.

If at all possible, though, I'd stick 2GB in. The optimal configuration in PPD terms is probably 3 clients on a quad - plus if Stanford decide to release WUs that use more memory you're a bit screwed with 1GB.

Just get the cheapest possible RAM that isn't going to die in five minutes. RAM timings won't really make any difference.

Cob · 13 Aug 2007 at 19:18

Definitely 2gb for a Quad. You'll be looking to run atleast 3 clients (four 4tw!) and they'll be needing in excess of 1gb.

shadowscotland · 13 Aug 2007 at 22:10

sorry to say it but I'm with the guys above - 2gb with a quad running 3 or more.

1GB for 2 clients and nothing else or 1 client and being used

Pilgrim57 · 13 Aug 2007 at 22:19

SiriusB said:
If you only plan on running one or two SMP clients then you might get away with 1GB. However, given how cheap memory is I'd be tempted to go with 2GB.

I'd echo that but are you sure Dapper Drake is the best choice?

RAM timings won't really make any difference.

Are you sure Mattus? On my A64 x2 lower CAS or Command rate makes a difference but maybe not on the almighty Core 2's [ heads back to shore as he realises he's out of his depth

]

Mattus · 14 Aug 2007 at 00:01

Pilgrim57 said:
Are you sure Mattus? On my A64 x2 lower CAS or Command rate makes a difference but maybe not on the almighty Core 2's [ heads back to shore as he realises he's out of his depth]

On A64s memory timings tend to make more difference, mainly because of the integrated memory controller. But on C2D they seem to be less important, mainly because the caches are so huge.

SiriusB · 14 Aug 2007 at 01:04

Correct. A64s integrated memory controller is far more sensitive to RAM frequency and timings than Intel chips.

In fact, there is very little gain in overclocking memory for C2Ds as the architecture doesn't depend on it nearly as much as A64.

MajorPart · 14 Aug 2007 at 03:39

Question I'm only running one WinSmp which starts 4 instances of Fahcore's why would i want to run two SMP's or is that just for linux?

Personally 2GB would suit the machine better and to be honest 2x1GB chips are hardly that much more than 2x512mb.

Cob · 14 Aug 2007 at 06:39

MajorPart said:
Question I'm only running one WinSmp which starts 4 instances of Fahcore's why would i want to run two SMP's or is that just for linux?

Personally 2GB would suit the machine better and to be honest 2x1GB chips are hardly that much more than 2x512mb.

You can run two or more SMP clients if one client doesn't max out your CPU.

Pilgrim57 · 14 Aug 2007 at 10:38

Mattus said:
On A64s memory timings tend to make more difference, mainly because of the integrated memory controller. But on C2D they seem to be less important, mainly because the caches are so huge.

"I see said the blindman ...." Thanks my new thing learned for the day

Biffa · 14 Aug 2007 at 10:47

I'll go with that, huge difference on my A64 between 1T and 2T timings on the RAM. Probably because its a 939 box with DDR1

magman · 17 Aug 2007 at 12:51

OK Guys, I'll go with the consensus and stick with 2 Gig in the specification.

Next question is though, what size PSU will I get away with. The CPU has a TDP of 105W and as I'm not going to be running disks or fancy graphics cards, I wonder what I can get away with?

Ideally, I would like to go for an efficient PSU, possibly something to the 80+ spec. with Active PFC, given that they will be running 24x7. I would also be tempted by a modular PSU, as a barebones system will only need the main motherboard power connectors.

I suspect I could get even away with a couple of good quality 600W supplies and some creative cabling.

Last but no means least are some heatsink recommendations. I'm planning to overclock the Q6600's, so I suspect that the stock heatsinks won't let me get the best results. Any suggestions on what works well with these processors? I'm currently leaning towards a Scythe Andy or Zalman 9500-AT.

Biffa · 17 Aug 2007 at 13:23

Best cooler for Q6600's is the Thermalright Ultra 120, however its expensive when you take into account the base cost plus you need to get a fan as well.

IMHO Best bang-per-buck is the Tuniq Tower 120

I've got the following PSU in my Q6600 mATX setup, to be honest you don't need anything uber as long as the rails are good, but I liked this one because it has special short cables for mATX setups: 500W Silverstone ST50EF-Plus-SC super silent, 80 PLUS, short cable v.1 ROHS PSU. Unfortunately I can't link to it but it should be easy to search for. Around or just under £50

If I was doing it again I'd probably get a Modular like the Corsair 520 for a few pounds more.

Bear in mind however that I was able to overclock the Q6600 stably with a 420W power supply so something like the 430W Tagan or Antec modular PSU's would be good and you'd save some dosh too.

Even barebones I'd go modular just to keep the mess to a minimum.

Biffa · 17 Aug 2007 at 13:50

OK this is what I would buy for a barebones Quad cruncher. These are all parts that I have had good results from in the past.

Obviously this is if you are buying from the shop here, I know you can get some components cheaper by shopping around. Then its a toss up between delivery costs and per component savings, but if you are buying multiple units it might be more worthwhile.

BFG 3DFuzion GeForce 6200 LE Turbo Cache 256MB DDR TV-Out/DVI (PCI-Express) - Retail £19.99 (£23.49)
Intel Core 2 Quad Pro Q6600 "LGA775 Kentsfield" 2.40GHz (1066FSB) - Retail £151.99 (£178.59)
OcUK 2GB (2x1GB) DDR2 PC2-8500C5 1066MHz Dual Channel Kit £59.99 (£70.49)
Gigabyte GA-G33M-DS2R Micro ATX (Socket 775) PCI-Express DDR2 Motherboard £64.99 (£76.36)
OcUK Huntkey 500W PSU OcUK Huntkey 500W PSU £31.99 (£37.59)

Sub Total : £328.95
Shipping : £8.95
VAT : £59.13
Total : £397.03

magman · 17 Aug 2007 at 16:24

Thanks Biffa,

I've picked up on most of these, though I'm tempted to spend a bit more money in the PSU, I've had my fingers burnt with cheaper PSU's on barebones crunchers before. I can get a good price on the Corsair MM520 from an OcUK competitor, were I get a staff discount, that gives me a branded PSU that is modular and has a longer warranty, so I suspect I'll go this route. There may even be a percentage point or two benefit in the efficiency of the Corsair PSU, which will help with the running costs and help to pay back the extra purchase costs.

In terms of heatsinks, I am planning to rack mount the boards, so a lower profile heatsink is to be preferred if possible, the Scythe Andy scores well here in performance against size. As with all things, its working out the best compromise that makes this kind of thing more interesting.

One further point though, would adding a graphics card make that much difference in performance over the onboard graphics with this G

shadowscotland · 17 Aug 2007 at 16:26

I posted a link to a x-bit article regarding 'super' cooler for quads and the Scythe Andy did quite well for it's cost

[email protected] 1.5v inside ATX case

CNPS9700 42/77 1x1700rmp fan
Scythe infinity 42/77 1x1200rmp fan
Scythe Andy 37/77 1x1200rmp fan
Big typhoon 35/71 1x1400rmp fan
U-120 ultra 41/69 1x1200rmp fan
Enzotech 37/68 1x1400rmp fan

Scythe Andy 36/72 1x2500rmp fan
CNPS9700 40/70 1x2800rmp fan
Scythe infinity 36/69 2x1200rmp fan
Big typhoon 33/69 1x2500rmp fan
U-120 ultra 39/66 2x1200rmp fan
Enzotech 36/66 1x2500rmp fan

Stick with onboard graphic if the board has them - But most good OC board don't have o/b graphics.....
Edit: *after a quick google* ...but biffa choice matx board above look a winner :cool:

Biffa · 17 Aug 2007 at 21:49

magman said:
One further point though, would adding a graphics card make that much difference in performance over the onboard graphics with this G

Yes, using the onboard gfx will reduce the ability and stability of overclocks according to reports.

I've even got a PCi Voodoo3 in one of my rigs rather than use the onboard gfx.

As for the other stuff, you are right about PSU's but so far the Huntkey has been pretty good for one of my rigs. But as I said before get the modular corsair, with all that stuff out in the open air, the less wires there are the better.

Re the size of the cooler, you are right I wasn't thinking, I've had reasonbale luck with my mATX rig with the Zalmans 8700 but they are a bit expensive. Nice and low though

In my bigrig I have a monster cooler. For the price at the time it was the best I could get, A Thermaltake BigTyp 120 VX CPU Cooler, its the big daddy remix of the old BigTyphoon, there are reputable sites out there beginning with H that rate this very highly.. but its huge! :eek:

magman · 17 Aug 2007 at 23:04

Thanks for the input guys.

I think I will go for the Corsair PSU, especially as can get it for a reasonable price.

I'd spotted the Gigabyte board a few weeks ago myself (I've been keeping an eye on MATX Socket 775 boards that are reasonable overclockers). I can again get these for a good price from another supplier, so these are a bit of a no-brainer. I've also spotted from some forums that this board has some issues with dividers, hence the choice of PC8500 memory as well. It looks like I will have to run some tests with them with graphics cards when I get them as well (Obviously, I'll post the results on here when I've had the time to run the tests).

I think I'll go for the Scythe Andy for the barebones crunchers, though I am looking at a Thermalright Ultra 120 Extreme for upgrading one of my cased systems from a E6300 to a Q6600 (the 6300 is going to be re-used in my new media PC, that's also part of this upgrade cycle).

Almost time to flash the cash methinks, just some time to look at any other extras I might need (Arctic Silver, TIM Clean, ATI 1950 Pro, New DVD player, etc.)

KE1HA · 18 Aug 2007 at 07:45

shadowscotland said:
I posted a link to a x-bit article regarding 'super' cooler for quads and the Scythe Andy did quite well for it's cost

[email protected] 1.5v inside ATX case

CNPS9700 42/77 1x1700rmp fan
Scythe infinity 42/77 1x1200rmp fan
Scythe Andy 37/77 1x1200rmp fan
Big typhoon 35/71 1x1400rmp fan
U-120 ultra 41/69 1x1200rmp fan
Enzotech 37/68 1x1400rmp fan

Scythe Andy 36/72 1x2500rmp fan
CNPS9700 40/70 1x2800rmp fan
Scythe infinity 36/69 2x1200rmp fan
Big typhoon 33/69 1x2500rmp fan
U-120 ultra 39/66 2x1200rmp fan
Enzotech 36/66 1x2500rmp fan

Stick with onboard graphic if the board has them - But most good OC board don't have o/b graphics.....
Edit: *after a quick google* ...but biffa choice matx board above look a winner

I use the Big Typhoon .. works well for me:

SYSTEM
CPU - E6800 OC to 3.668
MB - Asus P5W DH Deluxe
RAM - 2GB - Corsair CM2X1024-6400C4
Graphics - ATI 1950XTX
Thermal Compound - Antec Formula-5, Applied exactly as they recommend.

NOTE: I've not seen the SMP clients use more than 550MB of RAM yet. So 1GB would probably fit the bill.

No Load Temps

Loaded Core Temps

Loaded Tjunction Temps / Delta's

I run Intel D975XBX's with my Q6600's. Im letting them break in a bit before I crank of the watts and do any real temp analysis.
.