^^^
1.) balls, they prove how fast your system preforms in comparison to another system running the same benchmark, and depending on what there testing they prove a whole lot (like a full system test)
But benchmarks prove nothing in the real world.
2.) balls. how will it make your box slower ? running raid 0 *can* increase the load on the CPU very slightly, but thats normally down to the fact that it is/can process a lot more to/from the disk than a non raid 0 system
Its slower than Raid 1, the increased load on the PCI bus, or the cpu cycles if its software raid I would have thought just off of the top of my head. Much like shoving loads of USB attachments into a PC. If your a fan of benchmarks as you appear to be, every little helps right?
3.) balls. why ? faster access to needed OS files, faster loading times, faster swap file, i cant see any reason it would be slower ? and having run a few systems normally then in riad0, in my experience it sped things up, a lot
Its only faster on writes, its actually slower on reads.
4.) balls. how did you work that out ? no its not.
because he can read.
Raid Level 0 - Striping - Data is segmented and split onto multiple spindles.
Short Reads - Easily handles multiple simultaneous reads
Long Reads - Single operation can be split and processed in
parallel
Short Writes - Easily handles multiple simultaneous reads
Long Writes - Single operation can be split and processed in parallel
Redundancy - None
Cost - Good (no extra hardware)
Raid Level 1 - Mirroring - Duplicate data is kept on multiple splindles
Short Reads - Faster (shorter latency) since resolution can be from any of multiple disks
Long Reads - Faster since resolution can be from any of multiple disks
Short Writes - Slower since need to write to multiple disks
Long Writes - Slower since need to write to multiple disks
Redundancy - Excellent
Cost - Expensive - at least double the spindle cost
5,) balls. they might die, something bad might happen, but your in just the same boat as if you have 1 drive, 2 x 200 gig drives are better than 1 400 gig drive for speed, and drives dieing is pretty rare these days, especially without warning, as always back up your important data.
Your 2 times more likely to suffer a catastrophic failure, than you are with no raid, with raid 1 you are half as likely as a normal non-raid install to suffer any dataloss.
as for increased load on the PCI bus or increased CPU cycles....
do you really think the increased load on the PCI bus is going to slow down system preformance ? I dont understand where you got that from, even if your raid aray means your maxing out the PCI bus throughput, thats going to be directly preportunbal to the increased speed of the system because it can read/write data so much faster.
for the extra CPU cycles, the only difference Ive ever seen is that the CPU is working harder because its reading/writing so much more.
if I run some heavy compression software, copy a file from disk and put it back on the same disk my CPU is only just peaking at 20% usage (non raid here)
so the real bottle neck there in the system are the HD read/writes, not the CPU, and im pretty sure this will be the same 99% of the time. if I copy a file to a virtual ram drive, and do the same but using my ram instead of HD the cpus both run at 100% and its hellish fast (again confirming the HD bottle neck)
as for your little box of quote about raid, go and find some examples of raid cards that will read from 1 disk and not the other (to increas speed as it sugests) Ive never seen any, and Ive and a good look/read through difference raid cards, the whole point of raid1 is that everything that happens to one disk happens to the other too.
and I just plain dont beleave "RAID1 Long Reads - Faster since resolution can be from any of multiple disks"
balls to that, did you write it yourself ? raid 1 is faster becuase it can read from 1/2 as much from 2 disks in half the time it takes to read the same full thing from 2 disks ! (a major point of raid 1 being you read from both disks and check the data is identical)
1.) ...
Already been said - benchmarking proves nothing in real world.
2.) balls. how will it make your box slower ? running raid 0 *can* increase the load on the CPU very slightly, but thats normally down to the fact that it is/can process a lot more to/from the disk than a non raid 0 system
This is naff all to do with the CPU. Its the speed at which the disks can read/write data.
If you actually knew anything about RAID then you would know that the most important thing to get right with a RAID0 setup is the stripe size.
Getting the stripe size right so it actually increases performance depends on you knowing the size of the files that you are going to be working with.
Read this for a full explanation.
3.) balls. why ? faster access to needed OS files, faster loading times, faster swap file, i cant see any reason it would be slower ? and having run a few systems normally then in riad0, in my experience it sped things up, a lot
This relates to 2.) - OS installs contain lots of differently sized files. Putting your SWAP on raid0 would give some speed increase thou.
4.) balls. how did you work that out ? no its not.
More heads, less latency (see M3ta7H3ads post)
5,) balls. they might die, something bad might happen, but your in just the same boat as if you have 1 drive, 2 x 200 gig drives are better than 1 400 gig drive for speed, and drives dieing is pretty rare these days, especially without warning, as always back up your important data.
Its basic maths... again see M3ta7h3ads post.
As for the use "RAID 0+1" rubbish:
1.) Use RAID 10 not RAID 0+1 (see this
2.) Again getting stripe size is crucial
ok, ok, its important to get a good stripe size for what your using, but you havnt told my why running raid 0 is going to slow down my box yet ?
a raid 0 array with a badly set stripe size is still going to out preform a single disk.
as for the "the raid card has tell a disk to write a ***k file, then check its done that, then send the next one bla bla bla,. thats just plain wrong, the raid card sends data to/from the disk, the disk handels the rest and uses its cach to help, so thats running at 300mb/s (for SATA2) or even old IDE133, thats 133meg a sec, way faster than the disk can actually read/write from the platters.
so what if your OS install containes lots of different sized files ? weve already established that even with a badl set stripe size that raid0 is still faster then a single disk (and id argue its way faster)
yeah, so youve got twice the chance of a catastrophic failure, if i buy 2 lottery tickets ive got twice the chance of winning, its still naff all chance tho
and as said above, were talking about people running raid1 for the preformance increase here, this isnt people who have 2 identical drives, decide they might as well run raid and cant decide which rout to go it is.
so really were compairing a raid1 box to a non raid box, so backups are just as important either way arnt they ?
