Thread: Re: Opteron vs Xeon (Was: What to do with 6 disks?)
In terms of vendor specific models - Does anyone have any good/bad experiences/recommendations for a 4-way Opteron from Sun (v40z, 6 internal drives) or HP (DL585 5 internal drives) models? This is in comparison with the new Dell 6850 (it has PCIexpress, faster FSB 667MHz, which doesn't match up with AMD's total IO bandwidth, but much better than previous 6650s). Thanks, Anjan -----Original Message----- From: William Yu [mailto:wyu@talisys.com] Sent: Wednesday, April 20, 2005 11:10 AM To: pgsql-performance@postgresql.org Subject: Re: [PERFORM] Opteron vs Xeon (Was: What to do with 6 disks?) I posted this link a few months ago and there was some surprise over the difference in postgresql compared to other DBs. (Not much surprise in Opteron stomping on Xeon in pgsql as most people here have had that experience -- the surprise was in how much smaller the difference was in other DBs.) If it was across the board +100% in MS-SQL, MySQL, etc -- you can chalk in up to overall better CPU architecture. Most of the time though, the numbers I've seen show +0-30% for [insert DB here] and a huge whopping +++++ for pgsql. Why the pronounced preference for postgresql, I'm not sure if it was explained fully. BTW, the Anandtech test compares single CPU systems w/ 1GB of RAM. Go to dual/quad and SMP Xeon will suffer even more since it has to share a fixed amount of FSB/memory bandwidth amongst all CPUs. Xeons also seem to suffer more from context-switch storms. Go > 4GB of RAM and the Xeon suffers another hit due to the lack of a 64-bit IOMMU. Devices cannot map to addresses > 4GB which means the OS has to do extra work in copying data from/to > 4GB anytime you have IO. (Although this penalty might exist all the time in 64-bit mode for Xeon if Linux/Windows took the expedient and less-buggy route of using a single method versus checking whether target addresses are > or < 4GB.) Jeff Frost wrote: > On Tue, 19 Apr 2005, J. Andrew Rogers wrote: > >> I don't know about 2.5x faster (perhaps on specific types of loads), >> but the reason Opterons rock for database applications is their >> insanely good memory bandwidth and latency that scales much better >> than the Xeon. Opterons also have a ccNUMA-esque I/O fabric and two >> dedicated on-die memory channels *per processor* -- no shared bus >> there, closer to real UNIX server iron than a glorified PC. > > > Thanks J! That's exactly what I was suspecting it might be. Actually, > I found an anandtech benchmark that shows the Opteron coming in at close > to 2.0x performance: > > http://www.anandtech.com/linux/showdoc.aspx?i=2163&p=2 > > It's an Opteron 150 (2.4ghz) vs. Xeon 3.6ghz from August. I wonder if > the differences are more pronounced with the newer Opterons. > > -Jeff > > ---------------------------(end of broadcast)--------------------------- > TIP 9: the planner will ignore your desire to choose an index scan if your > joining column's datatypes do not match > ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org
Anjan Dave wrote: > In terms of vendor specific models - > > Does anyone have any good/bad experiences/recommendations for a 4-way > Opteron from Sun (v40z, 6 internal drives) or HP (DL585 5 internal > drives) models? > > This is in comparison with the new Dell 6850 (it has PCIexpress, faster > FSB 667MHz, which doesn't match up with AMD's total IO bandwidth, but > much better than previous 6650s). Dell cuts too many corners to be a good server. -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073
On Wednesday 20 April 2005 17:50, Bruce Momjian wrote: > Anjan Dave wrote: > > In terms of vendor specific models - > > > > Does anyone have any good/bad experiences/recommendations for a 4-way > > Opteron from Sun (v40z, 6 internal drives) or HP (DL585 5 internal > > drives) models? > > > > This is in comparison with the new Dell 6850 (it has PCIexpress, faster > > FSB 667MHz, which doesn't match up with AMD's total IO bandwidth, but > > much better than previous 6650s). > > Dell cuts too many corners to be a good server. Hi Which corners do Dell cut compared to the competition ? Thanks Christian
Anjan, > Does anyone have any good/bad experiences/recommendations for a 4-way > Opteron from Sun (v40z, 6 internal drives) or HP (DL585 5 internal > drives) models? Last I checked, the v40z only takes 5 drives, unless you yank the cd-rom and get an extra disk tray. That's the main defect of the model, the second being its truly phenominal noise level. Other than that (and price) and excellent Opteron machine. The HPs are at root pretty good machines -- and take 6 drives, so I expect you're mixed up there. However, they use HP's proprietary RAID controller which is seriously defective. So you need to factor replacing the RAID controller into the cost. > This is in comparison with the new Dell 6850 (it has PCIexpress, faster > FSB 667MHz, which doesn't match up with AMD's total IO bandwidth, but > much better than previous 6650s). Yes, but you can still expect the 6650 to have 1/2 the performance ... or less ... of the above-name models. It: 1) is Xeon 32-bit 2) uses a cheap northbridge which makes the Xeon's cache contention even worse 3) depending on the model and options, may ship with a cheap Adaptec raid card instead of an LSI or other good card If all you *need* is 1/2 the performance of an Opteron box, and you can get a good deal, then go for it. But don't be under the illusion that Dell is competitive with Sun, IBM, HP, Penguin or Microway on servers. -- --Josh Josh Berkus Aglio Database Solutions San Francisco
> The HPs are at root pretty good machines -- and take 6 drives, so I expect > you're mixed up there. However, they use HP's proprietary RAID controller > which is seriously defective. So you need to factor replacing the RAID > controller into the cost. Do you have any additional materials on what is defective with their raid controllers? --
On 4/20/05, Anjan Dave <adave@vantage.com> wrote: > In terms of vendor specific models - > > Does anyone have any good/bad experiences/recommendations for a 4-way > Opteron from Sun (v40z, 6 internal drives) or HP (DL585 5 internal > drives) models? We are going with the 90nm HPs for production. They "feel" like beefier boxes than the Suns, but the Suns cost a LOT less, IIRC. We're only using the internal drives for the OS. PG gets access to a fibre-channel array, HP StorageWorks 3000. I _can't wait_ to get this in. Our dev box is a 130nm DL585 with 16G of RAM and an HP SCSI array, and I have absolutely zero complaints. :) -- Mike Rylander mrylander@gmail.com GPLS -- PINES Development Database Developer http://open-ils.org
Josh Berkus <josh@agliodbs.com> writes: > Last I checked, the v40z only takes 5 drives, unless you yank the cd-rom and > get an extra disk tray. That's the main defect of the model, the second > being its truly phenominal noise level. Other than that (and price) and > excellent Opteron machine. Incidentally, Sun sells a bunch of v20z and v40z machines on Ebay as some kind of marketing strategy. You can pick one up for only a slightly absurd price if you're happy with the configurations listed there. (And if you're in the US). -- greg
Quoth christian@aspiro.no (Christian Sander Røsnes):
> On Wednesday 20 April 2005 17:50, Bruce Momjian wrote:
>> Anjan Dave wrote:
>> > In terms of vendor specific models -
>> >
>> > Does anyone have any good/bad experiences/recommendations for a
>> > 4-way Opteron from Sun (v40z, 6 internal drives) or HP (DL585 5
>> > internal drives) models?
>> >
>> > This is in comparison with the new Dell 6850 (it has PCIexpress,
>> > faster FSB 667MHz, which doesn't match up with AMD's total IO
>> > bandwidth, but much better than previous 6650s).
>>
>> Dell cuts too many corners to be a good server.
>
> Hi
>
> Which corners do Dell cut compared to the competition ?
They seem to be buying the "cheapest components of the week" such that
they need to customize BIOSes to make them work as opposed to getting
the "Grade A" stuff that works well out of the box.
We got a bunch of quad-Xeon boxes in; the MegaRAID controllers took
plenty o' revisits from Dell folk before they got sorta stable.
Dell replaced more SCSI drives on their theory that the problem was
bad disks than I care to remember. And if they were sufficiently
suspicious of the disk drives for that, that tells you that they don't
trust the disk they're selling terribly much, which leaves me even
less reassured...
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