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GreatInca
Posting Yak Master
102 Posts |
 Posted - 2002-01-10 : 17:51:12
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| My company is going to spend money in upgrading the web/sql servers.I was wondering, since SCSI costs 3x more than IDE for about 1.5-2x the performance, if it would be a crinimal act to use a 8 IDE drive 1+0 array as oppsed to a 4 SCSI drive 1+0 array, with each drive being twice as big and the total costs of the disks being the same?My DB is about 7gb, growing 50-100mb per day, with a good 70% of it being web tracking (clickstreams, sessions, visitors, searches, specific events, banners, errors). Search tracking alone is 2.5gb . Only about 1gb of the data is routinely active, and 2gb on nightly batches (maintanance, date based pre-agragateing of tracking), and pretty much all of it on weekly and monthly batches (non-date based pre-aggrating of the tracking data). |
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smccreadie
Aged Yak Warrior
505 Posts |
Posted - 2002-01-10 : 18:36:26
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| I'm not a hardware expert, but I believe the primary advantage of SCSI is its I/O speed. If you're doing operations that require a lot of I/O, SCSI is the way to go. From your description, it sounds like SCSI is more appropriate.Anybody else have comments? |
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bm1000
Starting Member
37 Posts |
Posted - 2002-01-10 : 19:38:38
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| I am not a hardware expert either, but I thought that IDE controllers could only perform one I/O at a time, whereas SCSI controllers allowed the disk drives to seek independently. |
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GreatInca
Posting Yak Master
102 Posts |
Posted - 2002-01-10 : 19:47:33
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| Does that apply to IDE vs. SCSI raid 1+0 controllers? Know where to read up more on that.DE drives are dirt cheap these days and havig twice as many drives and almost 4x the storage capacity as the same-priced scsi price looks attractive (and the ability to give the log and tempdb a pair of disks and still have 4 for the big db vs having everying on a single 1+0 4-drive scsi set). But if there are more performance gains with scsi raid vs ide raid than single scsi vs. single ide that might make the SCSI have uch more price/capacity/performance I'd like to know more about that stuff. |
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Onamuji
Aged Yak Warrior
504 Posts |
Posted - 2002-01-10 : 21:19:15
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Just something I found online:quote:
SCSI vs ATATo make a fair comparrison between modern SCSI (SCSI-3) and ATA (ATA/ATAPI-4) you have to look at two different scenarios: Single device and multiple device environments. Single device This scenario is common in desktop computers where you connect a single device to a single adapter and perform data transfers. There is practically no difference between the two interfaces, this holds for bandwidth as well as resource usage (CPU) as both interfaces use the most efficient way to transfer data. This means that there is no point in purchasing a generally speaking more expensive SCSI based system when the cheaper ATA interface would do an equally good job. Multi device This scenario is common in high-end desktop computers and servers where you connect multiple devices to one or more interface adapters. This is where SCSI has major advantages compared to ATA: Connectivity: The ATA interface can only address two devices while SCSI can address eight devices (Narrow SCSI), 16 devices (Wide SCSI), 32 (Very Wide SCSI) or 126 (FireWire). There are also many peripherals available to SCSI only and not ATA. Bandwidth: The demand for high transfer rates in servers can not be met using current ATA interfaces based on the two devices per adapter limit and even if it could carry more devices there simply isn't enough bandwidth and flexibility available for serious server application. Efficiency: The ATA devices lacks the intelligence to perform command queuing like their SCSI counterparts which can queue up to 256 commands per logical unit. Many SCSI hard disk drives aimed at the server market use extra logic to reschedule commands to minimize seek times and maximize throughput. This may not be evident by looking at desktop benchmarks but under heavy server loads, command queuing gives performance benefits. Dependability: Most high-end SCSI hard drives are quite expensive but there are good reasons for it. They can sustain higher temperatures and stay mechanically functional despite the expansion of the metal parts and and generelly have better build quality. The net result is that they are the natural choice for server applications.
... Perhaps that helps... I was going to get SCSI for a desktop but decided on ATA/100 since I could get drives twice the size for almost half the price and the speed was relatively the same ... as for RAIDING IDE drives it is no were near as fast as a SCSI raid there is just sick lag all the time... it also depends on what type of controller you use as well...- Onamuji |
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JamesH
Posting Yak Master
149 Posts |
Posted - 2002-01-11 : 09:16:56
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| Command queuing and mutliple device usage(only one device can use any given channel at a time on IDE whereas many SCSI Devices can operate simultaneously on one channel at the same time ) are the major reasons SCSI is better than IDE. JMHOJames |
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GreatInca
Posting Yak Master
102 Posts |
Posted - 2002-01-11 : 11:29:34
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| Thats good. I'll push for scsi. And a $50 IDE raid controller I was showed looks disgusting. |
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SCSI vs. IDE (performance vs. cost).