RAID controller to boost IOP

[nstgc]

In theory a RAID controller should be able to read the same bit of data from all hard drives at the same time, however, I don't know which ones do this. Could someone suggest a RAID controller (not pure software, and preferably pure hardware raid) which does this.

[edit] I recently purchased a Raptor (the 600 GB SATA III version...suppose to be the fastest SATA drive), but am very dissatisfied. Its hardly faster than my Samsung F3 and has this 20 GB region where performance is absolutely terrible. I'm looking at the new Adaptec 6405, but can't find the information I want.

[edit2] Also, I would hope this wouldn't increase latency too much.

[datora]

.

recently purchased a Raptor (the 600 GB SATA III version...suppose to be the fastest SATA drive)

Um ... do you mean SATA VII, or the 6.0 GB/sec specification ..?  Because the SATA III is a 3.0 GB/sec specification.  And, how is it connected to your system?  If directly via your motherboard, check your mobo spec and make sure it supports 6.0 GB/sec ..... and/or make sure the drive is being recognized at that spec.  Occasionally the drive needs to be jumpered to force the top specification, or a firmware &/or BIOS upgrade might be in order.

After that, the question is: are you trying to add in a RAID card to a PC workstation?  Create a stand-alone RAID system like a NAS, server, etc.?  I think you need to be using a PCIe slot of 4x or 8x to get top RAID performance; don't think you have to go all the way up to 16x.  But, a 1x PCIe will limit you, and a standard PCI will be as bad or worse.  Also, assuming a Win 7 64-bit environment ..?

Sorry I'm not up to speed on RAID controllers, so I won't be of much help there ... other than, from my casual knowledge, it seems that Intel add-on cards using PCIe at least at 4x are the minimum quality/standard you should be looking at if you want real performance.

[kitamesume]

hey i thought of an idea, if its possible, would using software raid on a ramdisk + hdd work?(by ramdisk i meant using your ram as a hdd by means of software)

yes it might lose some files right after shutting down the pc but what if the software raid knows that its a ramdisk and uses it as a buffer instead and rewrites it into the hdd in the background.

something like the ramdisk is being used as a raid1 style buffer, so on boot up the software raid fills up the ramdisk again with the most used files.

[vuzedome]

You're gonna need a lot of ram for that.

[Freedom Kira]

Have you tried just plugging into a mobo with Intel Rapid Storage Technology and using the onboard RAID?

Now you got me curious. Just how many people around here actually use RAID cards for performance?

These are the CDM results I get from using four of these SSDs in RAID 0 using Intel RST. It seems that the mobo is bottlenecking the IO, since, theoretically, it should be able to reach about 1GBps sequential R/W. Computer's specs were i5 2400S, 4GB low latency, P8H67-M EVO, Win7 Pro.

[nstgc]

@datora SATA III is the 6.0Gbps specification. I think it has some other nifty properties as well (in addtion to the doubled theoretical transfer rate), but they aren't as significant as the jump from SATA I to II (in fact I think its a bit silly for a mechanical drive).

I am looking at the PCIe type (in particular 4 and 8 lanes). PCI-X and PCIe 1x or 2x are a bit of a joke if you are looking for performance. This will be for a speed boost in my PC. I'm also looking for some redundency.

Don't assume Windows 7. I'd also like it to work with Linux. The last Raid card I had, in addtion to constantly losing drives, was absolutely not capatible with linux (piece of shit RockRAID 2310). Also, at that time, I didn't understand that there were RAID cards that weren't pure software, but also weren't pure hardware (I'm pretty sure the Adaptec I mentioned is such a card).

@Kitamesume I'm trying to avoid software. Also, that sounds less like a RAID and more like massive data caching. I don't have enough RAM for that anyway. That is a nifty idea though. I think thats the basis of one of Intel's SSDs actually.


In general, the reason I'm asking about IOPs is that for any RAID card that isn't total crap, the RAID 5 performance will aproximately scale under synthetic benchmarks (al beit at N-1) and I'm sure that a $300 card will have a decent RAID 1 algorithem. What I'm wondering is if there are any that can handle multiple requests at a time. Meaning that, if the CPU is asking for two small files, then it will assign one drive to one file and the other to the other file. Another thing I'm looking for is a "decent" (whatever that means) amount of cache. I assume that a large cache should help with larger files. If it does have cache, I definately want it to have a battery.

@Freedom Kira I don't use AMD processors. The problem with SSDs is that they are too small and too expensive. My windows partition is 440GB and I had to uninstall a couple games in order to defrag the drive.

[Freedom Kira]

What does AMD have to do with anything? o.O

[nstgc]

Intel doesn't make chipsets for AMD motherboards.

[kmarch]

Look into Areca raid controllers they are really nice!

[per]

First, is this for your workstation or a server?

The recommendations would be rather different depending on what the usecase is.

For a workstation one or two SSD:s will produce significantly more IOP:s than any classical drives can ever do.

For a server you will get way better performance and large capacity if you use something like a ZFS raid with the desired number of cheap 2Gb drives coupled with a dumb SATA controller and a SSD read/write cache drive (or multiple, depending on exactly how much IOP you neeed...)

And as for avoiding software, software raids almost always produce better performance, and is most definately safer (at least if you stay away from linux LLVM or Windows software raid).

It is, of course, somewhat hard to share between different operating systems.

Thus, a large NAS server is usually the best solution. With a 1Gb (or 2Gb, if you have 2x1Gb network cards and are willing to spend quite some time setting up bonding..) connection to the server you get high enough streaming bandwidth for most things, and the random access times will be very low if the NAS server has a few Gb of RAM and a SSD cache.

[nstgc]

@kmarch: It seems as if the Adaptec cards are more cost effecient. At the sub $200 rage they are all the same, but in the $250 - $350 range, Adaptec's seem better. In both cases both companies (as well as LSI and 3dware) seem to use real RAID (as in they have their own RAM and processor).

@per: I'm going to be using this for a desktop. I don't need IOPs. The reason I was asking about IOPs is as a means of seperating out cards that work with cards that work well. Also, since this is a desktop (running games and playing 1080p videos) I can't have the RAID eating up CPU time. Additionally, being able to move the RAID from one computer to another is very useful. I also like that many hardware RAID cards come with onboard RAM and the benchmarks I've seen show that for files smaller than the RAID cache, the limiting factor is the bus. So, for example, with a Adaptec 6405 (what I'll almost certainly get) I should be able to get 4GBps (and I expect 2.5) for files smaller than 512MB.

[kitamesume]

theres two reason why software raid would work on you better than what you thought it would, one is software raid hardly cost you anything and is no different than a cheap fake raid card, the other reason is that software raid is pretty much more safe than cheap fake raid cards and they're at the least hassle free. though a real raid setup is still the most effective.

a simple explanation for that is that a software raid itself is a software, thus avoiding hardware failure that could lead to "you know whats" and the fact that it is at software level so it will perform as if it was using your ram as a buffer and effectively using your sata controller. most likely the bottleneck would be placed on only two stuffs, which is your sata controller and your software itself. if your sata controller was slow to begin with then it would be performing according to what your sata controller can do. the software on the other hand, is how efficient and effective it manages your software raid, it should be at least faster than your combined drives.

PS: software raid doesn't insanely hog pc resources, mostly 10% at average during read/write operation. (on a dual core pc with 2ghz speed)
short note: if you have a slow pc to begin with, a raid setup wont do you much good, let alone investing on a $500+ real raid setup.

i suggest trying them both if you have them, and compare which performs better and which suits you better.

Edit: one question, what are you doing to make you move huge files so frequently? editing maybe?

[Freedom Kira]

Intel doesn't make chipsets for AMD motherboards.

I realize that, but if you don't use AMD, I don't see how this is a problem.

@Freedom Kira I don't use AMD processors.

Maybe by "don't" you meant "only?"