Rick Thomas <[email protected]> writes: > Interesting... > > I'm in the process of ordering a pair of R905's to run Eucalyptus for > a cloud-computing lab for the CC Department here at Rutgers. I'm > ordering them with Four Quad Core Opteron 2.2GHz (total of 16 cores) > but "only"[*] 16 GB of RAM (8 x 2GB sticks) with the intention of > adding Crucial (or other reputable 3rd-party) RAM after the project > gets started and we can gauge how much RAM we "really" want to put on > it. The theory is that adding processor chips is tricky but adding > RAM DIMMs is easy. > > That's the theory, anyway. Ski's experience gives me reason to > question that theory. Anybody got a better theory, before we go and > spend the money?
If you have a good ESD setup, and you are willing to wear a strap, it's all pretty easy. I buy SuperMicro SuperServers and plug in everything. It's maybe 20 minutes of work (then a day or two of burn in, but that's just loud noise in the garage) If you don't have a good ESD setup, or if you or your techs are not willing to use a wrist strap, yeah, let dell do it all. they pay a lot, but your reliability will go down measurably if you don't use ESD protection. On the other hand, with a little research, you should be able to find ram that fits in your server. that shouldn't be the hard part. > BTW: On the "customization" page for the R905, Dell has the warning > "Memory configurations with greater than 4 DIMMs per processor cause > memory to clock down to 533 MHz" (It's normally rated at 667 MHz). I > don't know if this relates to Ski's problem, but it caught my eye > anyway... This is true of almost everything. Usually it's automatic. But lt month I bought some of those new AMD G34 12 and 8 core boxes. I filled it up with 1333 ram, and the goddamn thing crashed. A lot. Well, I bought two servers, each with 32GiB ram of a different brand from different vendors (hynix from central computers, and Kingston from newegg) so I was pretty certain the ram wasn't bad. I bashed my head against the wall for a while until I noticed that the ram was actually running at 1333. I clocked the ram back, and the systems were quite happy. Figuring out compatable ram for your system can be pretty tricky until you become familiar with your arcatecture. the kingston website is an excelent resource. you type in your server or motherboard model and it will give you a list of compatable kingston ram, and usually has a word or two about the motherboard and it's quirks. (my experience has been that this list works just fine. I've never had them give me ram that didn't work.) I think crucial and corsair have similar tools The problem with the server manufacturers 'tested ram' list is that they test ram when the part comes out, and then they seem to loose interest, so especially with AMD systems where a motherboard may remain current for several years with the addition of bios upgrades to support newer CPUs, the manufacturers list of approved memory doesn't help much. _______________________________________________ Tech mailing list [email protected] http://lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
