Large-capacity memory

[fivemack]

Does anyone sell 4GB unbuffered non-ECC DDR3 sticks, so that I could put 16G in a Lynnfield or Shanghai system, or 24GB in a Bloomfield one?

Crucial doesn't: they have a wide variety of ECC ones, but I don't think P55 can use ECC memory.

G.Skill claims to make them, but none of their UK resellers appear to have them.

[Batalov]

I am monitoring these for myself. Half a year ago, there were none, for any price, and even DDR2's were just one or two vendors and very expensive. But now... I see 5 choices for single 4Gbs (one is even 1600MHz!) and some choices for pairs, triples and quads (indeed, many of them are G.Skill).

We could buy them here and FEDEX them to you. But it will be a bummer to replace.

[S485122]

In Belgium I could find Corsair and Crucial 4 GB DDR2 and DDR3 memory sticks. (at www.komplett.be for instance.) So they should be available in the United Kingdom as well.

Jacob

[fivemack]

At komplett.be I find

Crucial DDR3 1333MHz 4GB REG/ECC

but that's the registered ECC kind which would require a Xeon processor, and everything else seemed to be a kit.

(is 'geheugen' also used for human memory? It was the only word in the column of things-to-buy that I didn't recognise, but all the others clearly didn't mean memory)

EU customer regulation is very friendly, I believe I can buy something from Germany or Belgium and have an absolute right to a refund in a week, not only if it didn't work but if I didn't like the colour.

[S485122]

I gave this just as an example. I do not know if they send their stuff abroad since they have subsidiaries in Belgium, Denmark, Germany, the Netherlands... German E-Commerce sites for instance do not ship aborad most of the time.

But here are DDR3 4GB sticks in their offer :
Corsair Value DDR3 SO-DIMM 1066MHz 8GB
Kit w/2x 4GB, Unbuffered, 204pin (PC8500)
Komplett #: 441043/Art. nr. fabrikant: CM3X8GSDKIT1066

Not what I would buy those since they is relatively slow. It is a kit but of 2 * 4GB. I also suspect they would be no good for I7 or i5 architecture.

I found OCZ 12 GB kits of 1600 MHz and low voltage at another reseller...

The message that I wanted to convey is that it should be possible to find 4 GB sticks almost anywhere in Europe.

Jacob

[fivemack]

Corsair Value DDR3 SO-DIMM 1066MHz 8GB Kit w/2x 4GB

are laptop memory sticks for Macbook Pro.

The OCZ 12GB kits seem to be 6x2G rather than 3x4G

[Batalov]

If worse comes to worse (not available in the UK), you may want to buy straight from Taiwan. It takes a week or two to get it delivered though.
Did you look at the G.Skill's website, the resellers that they report in the UK? (I checked newegg.ca and already there, the choice is much less; the resellers don't quite want to risk it yet.)

Do you want to build a whole new rig, or update the i7? Preparing for the matrix of the century? If you keep 3x2, and add 3x4, it could be decent (the speed will be defined by the large chunks anyway). The anandtech review shows that we shouldn't quite dismiss 1333 or even 1066 memory. Still it is quite a bit of money even for 3x4. 700 bucks. Phew.

P.S. Mushkin sells direct. (they are expensive, but it's a name)

[Batalov]

Just wanted to drop another memory capsule here ...and maybe a year from now we may be amused by it (either "how cheap it used to be" or "how expensive it used to be").

DDR3 set of >12Gb solution still looks awfully expensive (especially for 1156); in fact, over a week or two, the choices became more limited and more expensive (too many RMAs, I guess).

But 16Gb = 2x(2x4Gb) of DDR2-800-CL5 can be now installed in a Phenom box for about $520 (with the spare 2x2x2Gb to be possibly traded off on ebay for $100-150).

[Batalov]

If we were to (re)build a system with W3520 (instead of 920) for just $20 more, on the same X58 m/b we could use ECC DDR3 memory, could we?
The manuals for the board and the chip suggest so. I never realized that the gap between 920 and W3520 was so narrow. And that a 3x4Gb ECC memory set would be actually cheaper than non-ECC, ironically?

[fivemack]

I have ended up buying a pair of Opteron 2380 CPUs (£180) and eight 4GB memory sticks (£350) from ebay; it looks as if I'll need to buy the motherboard new. Socket-F motherboards aren't impossibly expensive, though motherboard and PSU and two Socket-F HSFs and the case seem to be adding up to the thick end of £500. We've got some decent ATX cases with single-core P4 motherboards in at work, I'll see if I can get to one of those before they go for scrap.

This should be able to run filtering and matrix for 33-bit large-prime jobs, though the RAM's not terribly fast so the matrix step will be leisurely; ought to be able to manage 200-digit GNFS but probably not quite big enough for M1061. On the other hand it is big enough to do two 32-bit large-prime jobs at a time.

[fivemack]

And finally

nfsslave2@cow:~$ ssh nfsslave4@carthorse free
             total       used       free     shared    buffers     cached
Mem:      33081640    1257924   31823716          0     102124     249908
-/+ buffers/cache:     905892   32175748

Does anyone know why, when I run eight jobs on this eight-core machine, I often find that Linux (ubuntu-9.10) leaves one processor entirely idle and schedules two jobs onto another? 'mpstat -P ALL 2' tells me which is the idle processor and I can then use taskset to schedule one job onto it, at which point I have eight CPUs at 100%, but it seems very odd that I have to do this.