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Simon

Yet Another Raid Question ;)

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I know that having a RAID stripe doesnt actually help my software run smoother, but it does help loading it right? Like it helps booting XP.

Say i boot up my cinema4D... I know that a RAID doesnt help it perform better once its loaded (seeing as it depends on raw CPU power and doesnt have to read/write much from/to disk). But it does shorten the load time when i fire it up...

correct me if i'm wrong on this one plz!

So atm i'm thinking about getting a RAID0 of 2 x 36Gig Raptors (2 x 74Gig raptors is a lil too expensive for me ;)) and a 3rd standalone HD. I'd use the RAID0 for installed software and files i'm working on, and the single 3rd drive just for storing files like stuff i'm not working on anymore, isos, movies, mp3s, ...things that dont require the good STR of the RAID.

Any thoughts on that (or any stuff i'm missing?)

Thanks,

Simon

ps. Yes, i've read the faq ;p

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Why? 2 x 36Gig raptors give me only marginally higher access times but 'double' the STR. I have a P4C800-E deluxe mobo so i already have a raid controller onboard. And seeing as the 36gig raptor is half the price of the 74gig version the cost is the same.

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marginally higher access times but 'double' the STR.
I have been an advocate for RAID 0 for a long time but I do know their are drawbacks. It really depends on what types of files you have. If they are all small < a few MB the single drive will be faster as the higher access time will be the largest factor. If they are large and you need to load them sequentially the RAID setup would be better. If you think raid would help network filesharing performance you are in most cases wrong. As GBit ethernet will not be fast enough to keep up with most single drives unless you have a 64bit 66 MHz PCI bus or better. Also there is a reduced reliability and increased noise, heat and power draw with the raid system.

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But any idea on the loading time of software anyone? Is that more access time related or STR related?

that depends on quite a few things

firmware

drives

chaching

stripe size

apps/files

karma

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As GBit ethernet will not be fast enough to keep up with most single drives unless you have a 64bit 66 MHz PCI bus or better.

???

It's easy to see where modern drives cannot continuously fill even a 100Mbit connection. All it takes are multiple users to make the drive come to its knees.

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All it takes are multiple users to make the drive come to its knees.

That is correct, but RAID 0 will not help this at all. Here you need multiple independent drives and data that is scattered on them.

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So ... err.. I kinda thought about it some more and came to this conclusion:

Booting up apps or games or whatever is a proces where small, non sequential files are being read into memory. So booting stuff would get more benefit from good access times (a raptor) instead of good STR (a raid of 2 normal drives).

Ok then my solution of a raid of 2 raptors would seem best so i get good access times & good STR.

Plz do correct me if i made some mistakes in my reasoning ;)

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Reason why I said the single 74GB is look at the comparison between them both in the Performance database (see top of forum page)

The 74GB outperforms the 36GB.

This should be most of the time.

A RAID-0 will not be most of the time.

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Simon,

Booting up apps or games or whatever is a proces where small, non sequential files are being read into memory. So booting stuff would get more benefit from good access times (a raptor) instead of good STR (a raid of 2 normal drives).

Actually the Windows XP boot process is highly sequential in nature. It is optimized to be that way. Booting is one of the few real world tasks in which RAID 0 offers a demonstrable performance improvement.

Additionally NTFS 3.1 optimizes application load times in the same way.

Despite this however, it has been demonstrated and published (in the SR FAQ) that the benefits of striping are negligeable except during boot up.

For specific results on application load times you should search the archives. Many people quote x seconds for single disk x seconds for the array. The difference is almost always insignificant. You should have searched the archives before posting this. There is enough information to keep you busy for days.

Most importantly,

It is worth noting that, in the situations where hard drive performance is most noticeable to the end user, mainly multitasking I/Os (e.g. loading an application with a file copy in the background), a RAID 0 array will perform significantly slower than using the two disks independently. My post in this thread which is also currently on the front page explains this.

My advice is to get the WD740GD; it is significantly faster than its predecessor.

In the future,

Please search and read the FAQ. At the very least, look through the recent topics. There are currently approximately 5+ RAID 0 threads on the first page alone. This is repeated everyday. It is simply good ettiquette to not crowd a forum with redundant posts. I have posted 3 variations of this very post today. I do it because I would like to help and contribute to the general knowledge of the community. Redundancy wastes everyone's time however.

Do well.

Jonathan Guilbault.

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