![[H]ard|Forum](/styles/hardforum/xenforo/logo_dark.png){kind=logo}
Navigation
Install the app
How to install the app on iOS
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
More options
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
PCI-X Adapter
- Thread starter mykel31
- Start date
epimetheus
Gawd
- Joined
- Jun 20, 2004
- Messages
- 815
Putting a RAID card in a PCI slot is going to kill any bandwidth advantage that RAID will give you. A PCI slot is 32bit @ 33MHz. That's only 132MB/s. If you're looking for anything more than single drive performance you're going to see bottlenecks.
mykel31 - if you haven't got the card yet - have you looked into PCIe cards? If you've got an open PCIe slot, especially a free PCIe x4 or x16 slot, there may be alternatives to consider.
First... I'm hardly a raid expert, my experience is limited to benchmarking my own "stuff". I've got a PCI-X card (low end) in my unRaid server, mostly for its number of ports. The drives on that box don't ever get updated, and new files (cd/dvd rips and recorded shows) get written to it just a couple times a week. So I've got some practical experience in the limits of PCI-X in a PCI slot.
That LSI card is a sweet looking card. epimetheus is correct, the PCI bus will limit its bandwidth. This is a bigger deal if more than one user (or tasks) are trying to get at data on drives connected to the card, more so when one of those operations is saving/updating a file of signficant size.
For a single user, the bandwidth limit will mostly hit you when your copying large files to/from a disk on it, maybe more so if it is from one disk to another on that card. PCI bus has a theoretical limit of 133MB/s, but whenever I've measured it, about 100MB/s seems to be the real limit. Considering quality hard drives of the current generation (WD640gb, single platter Seagate 500gb, Velociraptor) have peak transfer rates better than 100MB/s, the bandwidth limitation really starts to hurt right away.
I suspect (but have no evidence) that a lot of the benefits you get with the processor and ram on that card will be somewhat or maybe mostly negated because of the bus. Assuming you are getting that card for those features, consider looking for PCIe based cards if you haven't yet.
First... I'm hardly a raid expert, my experience is limited to benchmarking my own "stuff". I've got a PCI-X card (low end) in my unRaid server, mostly for its number of ports. The drives on that box don't ever get updated, and new files (cd/dvd rips and recorded shows) get written to it just a couple times a week. So I've got some practical experience in the limits of PCI-X in a PCI slot.
That LSI card is a sweet looking card. epimetheus is correct, the PCI bus will limit its bandwidth. This is a bigger deal if more than one user (or tasks) are trying to get at data on drives connected to the card, more so when one of those operations is saving/updating a file of signficant size.
For a single user, the bandwidth limit will mostly hit you when your copying large files to/from a disk on it, maybe more so if it is from one disk to another on that card. PCI bus has a theoretical limit of 133MB/s, but whenever I've measured it, about 100MB/s seems to be the real limit. Considering quality hard drives of the current generation (WD640gb, single platter Seagate 500gb, Velociraptor) have peak transfer rates better than 100MB/s, the bandwidth limitation really starts to hurt right away.
I suspect (but have no evidence) that a lot of the benefits you get with the processor and ram on that card will be somewhat or maybe mostly negated because of the bus. Assuming you are getting that card for those features, consider looking for PCIe based cards if you haven't yet.