While I understand being economical, at some point one crosses the line to being penny wise and pound foolish.
How much is the data on this server going to be worth? How much much will it cost you to recover or restore it (assuming that is even possible if you lose it)? If your data is worth nothing or the cost to recover or restore it is negligible, then you don't need (nor should want) a DB server. You'll get higher performance at less cost via a number of other methods. OTOH, if you data _does_ have value by any of the above metrics, then it is worth it to pay attention to reliable, safe, fast, physical IO. Battery backed HD caches of appropriate size are usually well worth the $, as they pay for themselves (and then some) with the first data loss they prevent. RAID 5 means you are _always_ only 2 HDs from data loss, and 1 HD from a serious performance hit. Part of the trade-off with using SATA HDs that cost 1/3-1/4 their U320 15Krpm brethren is that such circumstances are +FAR+ more likely with SATA HDs. If you are not going to use RAID 10 because of cost issues, then spend the $ to get the biggest battery backed cache you can afford and justify as being cheaper than what the proper RAID 6 or RAID 10 setup would cost you. Even if you are going to use SW RAID and the controller will just be a JBOD controller. On the general subject of costs... At this writing, SODIMM RAM costs ~$100 (US) per GB. Standard DIMMs cost ~$75 per GB unless you buy 4GB ones, in which case they cost ~$100 per GB. The "sweet spot" in SATA HD pricing is ~$160 for 320GB at 7200rpm (don't buy the 36GB or 74GB WD Raptors, they are no longer worth it). If you are careful you can get SATA HD's with 16MB rather than 8MB buffers for that price. Each such HD will give you ~50MB/s of raw Average Sustained Transfer Rate. Decent x86 compatible CPUs are available for ~$200-$400 apiece. Rarely will a commodity HW DB server need a more high end CPU. Some of the above numbers rate to either fall to 1/2 cost or 2x in value for the dollar within the next 6-9 months, and all of them will within the next 18 months. And so will RAID controller costs. Your salary will hopefully not degrade at that rate, and it is unlikely that your value for the dollar will increase at that rate. Nor is it likely that data worth putting on a DB server will do so. Figure out what your required performance and reliability for the next 18 months is going to be, and buy the stuff from the above list that will sustain that. No matter what. Anything less rates _highly_ to end up costing you and your organization more money within the next 18months than you will "save" in initial acquisition cost. Ron -----Original Message----- From: PFC <[EMAIL PROTECTED]> Sent: Sep 24, 2005 12:27 PM Subject: Re: [PERFORM] Advice on RAID card > It looks like a rebranded low end Adaptec 64MB PCI-X <-> SATA RAID card. > Looks like the 64MB buffer is not upgradable. > Looks like it's SATA, not SATA II Yeah, that's exactly what it is. I can get one for 150 Euro, the Areca is at least 600. This is for a budget server so while it would be nice to have all the high-tech stuff, it's not the point. My question was raher, is it one of the crap RAID5 cards which are actually SLOWER than plain IDE disks, or is it decent, even though low-end (and cheap), and worth it compared to software RAID5 ? > Assuming you are not building 1U boxes, get one of the full height > cards and order it with the maximum size buffer you can afford. > The cards take 1 SODIMM, so that will be a max of 1GB or 2GB > depending on whether 2GB SODIMMs are available to you yet. It's for a budget dev server which should have RAID5 for reliability, but not necessarily stellar performance (and price). I asked about this card because I can get one at a good price. Thanks for taking the time to answer. ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org