[Solved] Speed: RAID* vs. SSD vs. hdd?!

I have no direct experience with SSD's, but the newer ones are sure to be faster than HDD's of any form. They are a lot more expensive per GB. But some combination of SSD for really fast response in the OS drive (including mounting games on it, if that's your speed need) with large standard HDD's would be fast for most things IF you can afford the combo.

I am not a gamer. However, what I read all the time is that the speed advantage of RAID0 for gamers over plain modern hard drives is pretty small, but measurable. RAID0 has a risk involved - because BOTH drives in the array MUST be functioning, a failure in either kills the entire "drive" and you lose everything on the array, so the risk of data loss is twice as high as for a single drive. But back to speed. Although Raptors were very popular as speed leaders, today's WD Black disks are really fast and come in VERY large capacities for similar cost. WD Green disks are large and use less power, but are slower.

RAID1 gives you some security by virtue of maintaining TWO copies of everything with the ability to fall back on only one of those if the other goes bad, then replacing the faulty one and rebuilding the array. It still is NOT a substitute for a true backup system. RAID1 will be a bit slower than a single disk for many operations. And of course you get 1 disk's worth of data capacity for 2 disk's worth of cost. With RAID0 you get 2 disk's worth of data capacity for 2 disk's worth of cost and a bit faster performance (for most operations) than a single fast modern disk, but with increased risk of data loss. But unless you want ultimate speed, sometimes the best option (and most cost-effective per GB of usable space) is a fast modern single disk like a WD Black.

Either RAID0 or RAID1 is done with TWO disks in an array. With 4 disks you could create two arrays (of either type or one of each) of 2 disks each, but not one 4-disk array. But why would you? If, for example, you decided to go for two RAID0 arrays for the small speed advantage of that technology, you could get the same speed with higher capacity for the same price by setting up ONE RAID0 array with 2 larger HDD units.

RAID1 is NOT a backup system. Although it may cost slightly more than putting 2 normal internal drives into the case in a RAID1 array, having one internal drive to use and a second external drive for the backups is better. You can and should make the backup copies and VERIFY that they are valid copies (a step not followed often enough!), then disconnect the external completely to protect it against electrical glitches, viruses, etc. Even better, carry it offsite until the next time it is needed.

Did some quick price comparisons at a site you linked. Smallest WD Black is 500 GB at $79, but going up to 1000 GB costs you $119, a better deal than two smaller ones for RAID! Newest Raptor will be faster (on average Seek time) but will cost $189 for 150 GB, or $287 for 300 GB. Ouch!

A review that the site references shows (for slightly different earlier models) that for gaming applications, the WD blacks in RAID0 were significantly faster than a single disk, BUT the RAID0 system had NO speed advantage in most other application types, for unknown subtle reasons.

Regarding RAID controllers, you have three options. You can buy an add-on card for the PCIe bus that gives you a RAID controller. The low-priced ones of these provide mainly a software system that runs in the CPU, while the much better (and much more expensive) ones have their own processors to handle the work, and have many more RAID options. For your use they may not be necessary. And remember that these systems must use the PCI bus, so WHICH PCI bus you use makes a big difference in speed. Many mobo's now contain chipsets that have RAID built in, at least for RAID0 and 1, and that makes this controller system cheap. These really are software-only systems that use the CPU again, but they are well integrated. The risk with them is what happens when your mobo fails? RAID is not well standardized, so in general you will not be able to use RAID disks written in one system on a different system - you just lost your data! BUT some chip makers claim / guarantee that they will make future models to use the SAME RAID algorithms as their older ones, so you can move drives from one mobo to another as long as you stick to the same chipset system. I did this recently. Had an Abit mobo I selected, among other reasons, because it had an nVidia chipset who guaranteed this and I was setting up RAID1. It failed after 1½ years (appears to be bad capacitors) and I replaced it with a Gigabyte mobo with all the required features including a slightly more recent nVidia chipset. First boot, it just worked perfectly, no adjustments required!! Woohoo!! So for me this was successful.

Third option is to use RAID capability included for free (software app again) in Windows, but I have no experience with this and some people report it is less reliable. I don't know.

So in summary for RAID controllers: Add-on controller card in PCIe slot can have advanced capabilities and speed advantage in certain types of RAID (you may not use), costs money (maybe quite a bit, depending on choice), but probably allows you to recover from RAID controller failure by replacing it with a similar card from the SAME supplier. RAID control built into mobo chipset and BIOS is cheap and easy, but controller (mobo) failure recovery will depend on getting a new mobo with compatible chipset and RAID software built in. Windows RAID application is free, MAY be easy to recover from "RAID controller failure", but has had mixed performance reviews.