SCSI RAID 0 vs RAID 5 for gaming system (only games)

First: an U160 controller can't provide the necessary bandwidth for 4 10krpm drives, it can hardly manage 3 of them (assuming the maximum transfer rate in contingous read/write)
Second: if you only intend to play games, RAID0 give no performance increase. It can reduce a little the loading time, but no more than this. You'll notice a big loading time reduction with 2HD vs 1, but with 3 vs 2 you'll notice quite none performance increase.

I'd personally buy a 250GB SATA drive for this system and reuse the SCSI drives in another system (video editing and other serious things) arranged in RAID5.

But it's only my opinion :-)

Well, like maury73 said you're going to be starved on bandwidth. As for loading time, that's up to the ram unless the game is on the paging file. Personally, I'd go with RAID 5 if you're going to use the drives just so you have redundancy. I mean you don't have to just use it for games, you can put anything else you want on there.

Honestly though, get a SATA drive and use that.

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What facts are you basing this on? The card can handel 15 devices, yes on a 32 bit bus the bandwith will become saturdated at rare times, but it's a two channel card that can support a 128mb write back dimm. The rate at what they spin has no baring what so ever in the case.

Aren't you able to have more than one array on the controller, or am I coming way out of left field?

Why not put 2 in a Raid 0 and store your games and other non-essentials on it and the 3 in a RAID 5 for your OS, and important data?

The drive cage I have puts all the drives onto one channel. This system is only going to have games on it, nothing else, not even used for browsing the web. Since I already own the hardware, in this case it is actually cheaper for me to go the route of using SCSI instead of SATA. I believe a 5 disk SCSI array would be faster than any single SATA drive on the market, or am I just hoping?

Any 10krpm drive, the worse you can found, will have a trasfer rate of 60MB/s. In order to setup a RAID0 array you must connect the drive on the same channel and 5 drives @60MB/s gives you 300MB/s total that is far over the maximum bandwidth of the channel.
Always remember that SCSI is a bus like IDE, the bandwidth is shared between all the devices connected on the same channel, never confuse with SATA on which every device has its own channel with 150 or 300 MB/s bandwidth.

Any 10krpm drive, the worse you can found, will have a trasfer rate of 60MB/s. In order to setup a RAID0 array you must connect the drive on the same channel and 5 drives @60MB/s gives you 300MB/s total that is far over the maximum bandwidth of the channel.
Always remember that SCSI is a bus like IDE, the bandwidth is shared between all the devices connected on the same channel, never confuse with SATA on which every device has its own channel with 150 or 300 MB/s bandwidth.
Your not understanding the SCSI technology at all and prove to lack knowledge on the Sata. A SCSI bus is nothing like IDE... The IO's on the SCSI interface will be delayed yes, but this is only on a PCI bus, not on the PIC-X bus. Your trying to use logic to explain SCSI Differentials, same with SATA bandwidths. Also drive speed means little in just expelling internal and external transfer rates. In this case 160 drives throughput from within the array will be calculated at the Proc onboard which is 80mhz, but on the a PIC bus will be 40mhz. You cannot use logic (IE simply multiply what you think the transfer rate of one termination will be)to explain how the interface perform in any given array.

aryaba:

U160 drives would be less than or perhaps equal to a Sata raid 5 array for single user use, depending on the supporting environment. U320 and Serial Attached SCSI are infront of Raptors in performance, but only in an optimal (expensive) environments. Meaning, on average with a u320 controller card you would need the PCI-X 133 interface to get optimal positive results. U320 cards on a PCI 2.0 bus work at 160 and slower anyway.
Not to hijack the thread, but to do what your looking for: a simple Raptor array would be cheaper and more practicle. SCSI involved more power, active colling, and cash.

This would be true, however, I already have 5x73 SCSI 10k drives, a RAID controller and a SCSI hot-swap cage just sitting in my parts pile doing nothing.

It seems that YOU absolutely don't know how SCSI bus works.
Read something on the argument before posting anymore.

Here is the argument. Your knowledge it topical at best. Your logic is flawed and does not represent how the controller handles an asynchronous array.


Again the argument: Your basing this on at-glance theory's. A SCSI bus is not like IDE, short and simple. How about YOU read something about the technology before posting?

LIke I said, just go with RAID 5. You're going to be gaming so from the startup it might be just a smidge faster than a SATA drive but once it's on the RAM it has nothing to do with the hdd. As for being starved on bandwidth, don't worry about it too much. You might come close to saturating the channel, but I don't think you'll be able to do it with gaming.

A couple of comments:

1. In a gaming machine, you're looking for speed, not fault tolerance. RAID 0 is much more in line with this goal than RAID 5.

2. It's not a good idea to place the boot drive on a RAID 5 array. The AMI Elite RAID card is a good RAID card, but it is at least 1 generation (probably 2) behind current RAID implementations. The RAID 5 write speed won't be outstanding. The boot process and overall system speed will suffer with the constant boot drive writes to a RAID 5 array.

3. Unless you're going to get a server board, you're going to have to use the AMI RAID controller in a standard PCI 2.2 slot (32-bit, 33 MHz). As such, the maximum sustainable throughput of the array will be limited by the PCI bus bandwidth, and will top out at 95-120 MB/sec depending on the motherboard and chipset. So forget all the theories of shared SCSI bus bandwidth, drive capabilities, etc. 95-120 MB/sec is all you're going to get.

4. If you do decide to get a server board to attempt to achieve higher bandwidth on this card, be aware that this card is PCI 2.2 compliant (universal voltage 3.3v/5.0v, 64-bit, 66 MHz). It is NOT PCI-X 1.0 compliant. If you put it in a PCI-X 1.0 slot on a properly designed motherboard, it will probably run, but only at 66 MHz. There are some PCI-X implementations where it won't run.

5. Since I recommend against RAID 5 for the boot drive, that leaves RAID 0 or RAID 1 for the boot drive. A 2 or 3 drive RAID 0 is going to top out the PCI bus bandwidth, so there's no use in going to a 4 drive or 5 drive RAID 0. Why not consider a 2-drive RAID 1 for the boot drive and a 3 drive RAID 0 for the games? The card should be able to handle 2 separate arrays on the same bus. Or, if you also have important data you want to back up, do a 2-drive RAID 0 for the boot drive and games, and a 3-drive RAID 5 for fault-tolerant storage. Or, you could conceivably do a 4-drive RAID 10 for boot, games, and fault-tolerant storage and an extra 5th drive as a hot spare or pagefile/scratch drive.

For all the theoretical discussions of bandwidth here, there is one that no one has mentioned:

1. When placed in any type of array in a system, it will load Windows and games at some xx MB/sec.

2. Currently, the 5 drives and card are moving data at 0 MB/sec.

Since you have it and it's free, put the thing in a system and be happy. It's not like it's competing with another solution, because it's FREE. 8)