Hardware RAID controller card question

[Bullitt]

Obviously, I dont have any 64-bit pci slots on my motherboard. But I'd like to set up a RAID5 setup for my system. I want hardware raid since I'm of the opinion that software raid = teh suxxor.

I was looking at a somewhat entry-level LSI RAID card, but its meant for a 64-bit/66MHZ pci slot. I was also under the impression that it would work in a 32-bit slot.
For example product linkage

I'm planning on using all 4 channels paired with some inexpensive hitachi 250 gig'ers so I'm not throwing a large amount of money into it. I estimate $700 or so. Anyways, I'm not expecting the world of performance, but I would like to have some Uummphh! in my disk access and throughput.

How bad am I going to limit myself with 32-bit PCI? I'm under the impression that I have 133MB/sec of available bandwidth on that bus. Will I exceed this with a 3+1 drive RAID5 setup?

 

[Top Nurse]

As far as the 66/33Mhz PCI slot I don't believe that card will go in a regular PCI slot. If you go to the LSI Logic website it is obviously not a 32 bit card. Perhaps you should check out the Promise board at:

http://http://www.newegg.com/app/viewProductDesc.asp?description=16-102-035&depa=0

www.promise.com/product/product_detail_eng.asp?productId=112&familyId=2


If you like this card perhaps we could come to some kind of arrangement as I was considering selling mine. It is still in the box and never been powered up and has 256Mb off ECC Micron ram in it

 

[Bullitt]

Hrm, I was refering to this thread when it was mentioned that they were backwards compatible.

Also, I wanted real hardware raid to make use in my 'nix environment. This may be real hardware raid, but a quick google search shows a lot of people having difficulty getting this sucker to work in "hardware" mode. Apparently their drivers are closed-source (something I want to avoid). I'm sure it will work like a dream in fakeraid mode.

 

[tdg]

64 bit PCI cards are backwords compatible with 32 bit PCI slots. I'm using several 64 bit PCI RAID controllers in regular slots.

 

[UICompE02]

64 bit PCI cards are backwords compatible with 32 bit PCI slots. I'm using several 64 bit PCI RAID controllers in regular slots.

Yes, this is absolutely right. And to further extend this, PCI-X cards are also backwards compatible with conventional 32-bit PCI slots.

 

[twistacatz]

Your write speeds well not be that great 5-15mb a second, your read speeds well be nice at around 25-80MB/s

 

[Bullitt]

Your write speeds well not be that great 5-15mb a second, your read speeds well be nice at around 25-80MB/s

as measured by what?

 

[twistacatz]

3Ware Bench

 

[agrikk]

Yes, this is absolutely right. And to further extend this, PCI-X cards are also backwards compatible with conventional 32-bit PCI slots.

Not all 66/64 boards are backwards compatible. I read somewhere that there are versions of 66/64 PCI that are 3.3 volt instead of 5 volt (or the other way around) and while most nowadays are smart enough to detect what voltage you are running and downshift accordingly, there are some boards that can only run one or the other. I'm pretty sure the Compaq 5403 Array Controller is one of them.

Also, take a look at the Adaptec 2810SA Raid Controller. $444 +s/h from newegg gives you eight ports of sata goodness on a fully backwards compatible 66mhz/64-bit card.

I just bought and installed this card into a server for a pal, mounting 5 200gb drives in RAID-5 (leaving three more spots open for expansion at some future date) in a non-server board with 32-bit PCI slots. I haven't run any benchmarks on it yet, but it feels responsive when moving all kinds of 10 gig test files off and onto it in testing.

 

[UICompE02]

Not all 66/64 boards are backwards compatible. I read somewhere that there are versions of 66/64 PCI that are 3.3 volt instead of 5 volt (or the other way around) and while most nowadays are smart enough to detect what voltage you are running and downshift accordingly, there are some boards that can only run one or the other. I'm pretty sure the Compaq 5403 Array Controller is one of them.

Actually, it's not the fact that it's a 64-bit card that makes it not compatible. All forms of PCI (excluding PCI-Express, of course) have 3.3V, 5V, and Universal versions of the cards and slots. They are all keyed differently to prevent you from plugging one type into another (except unversal, which supports both), but be sure to check which voltage your system is before buying an adapter.

 

[defakto]

64 bit cards are compatible with 32 bit slots, even if the card is too long for teh slot. THe card can hang over teh edge of the slot without any issues. I've got a 64 bit raid controller running on a 32 bit slot in my other system. Hangs past the end of the pci slot without an issue.

 

[Bullitt]

3Ware Bench

Pshew!!! I thought those numbers looked really low!!

Drives: Maxtor 4G160J8 D540X (160g @ 5400 rpm)

Ok, I'd expect better than those numbers and with somewhat more modern hardware (8MB cache drives and 7200rpm units).

I suppose I guess I'm looking at maxing out my pci bus? Is that a bottleneck I should expect with any raid5 (on a pci 32bit/33mhz) solution?

 

[sixandout]

i forgot where i read but i have a promise with 4 hds. one of the reviews compared it on a 64bit motherboard, versus a 32 bit board. the numbers for a similar 64 bit pci was almost 2 times better in some tests. forgot what tests they ran. the tests were run in various configs with different number of harddrives. they maxed out the pci bandwidth with 3 drives on the 32 bit motherboard. i bought the controller anyways. basically using the card on a 64 bit pci slot was much better than using it on a 32 bit pci slot. but i have a promise so maybe that card sucks.

 

[agrikk]

I suppose I guess I'm looking at maxing out my pci bus? Is that a bottleneck I should expect with any raid5 (on a pci 32bit/33mhz) solution?

I'm pretty sure that you'll saturate the 32/33 bus with any RAID card populated with any modern drive. In fact, pretty much everything will saturate old PCI Busses. Except maybe a WinModem...

I found this really short, descriptive article on the various PCI versions out there. The last few pages are a promotion for Digi stuff, but the first bunch of slides are really helpful for getting the quick and dirty lowdown on PCI.