Making a Flash Raid thing

[wellmad]

Hi,

I read this guide on thg recently - The project: Using Compact Flash cards to build an SSD : The Definitive Guide to Building an SSD Using Compact Flash cards

The article got totally slated so I gues that isn't the best way to do it, but I want to do something similar. basically, I want to make something that appears to the PC as a normal HDD so I can install Windows on it, but I want it to be as fast as it could possibly be so that Windows boots and apps luanch really fast.

I figure four 16Gb flash cards would be enough as I just want Windows XP or Vista plus maybe 30 apps including a few games. I don't need to store anything locally as I have a nice little nas (and could always bung in a sata hdd if needed)

I'm not sure where to start, would a flash/SATA combo be the best, or flash/IDE? Any recommendations, tips or advice?

[LegacyOne]

Your be better off getting four 36 Gb Western Digital Raptor and putting them as RAID 5, but if you really want to go with the Flash Raid thing I would go with the flash/SATA combo on a Intel RAID chip for max speed.

[Funkstar]

the dificult part is getting fast memory cards that don't identify themselfs as removable storage.

The current speed king is the SanDisk Extreme IV Ducati edition, but windows will only see them as removable storage.

You could try them on a RAID card, it may let you use them as a fixed disk.

You do get 'industrial' cards that appear as a regular drive, but they are more expensive and not as fast.

Why no just get an actual SSD?

Computer hardware and software at amazing prices, available online from Scan Computers UK

EDIT: This one sounds pretty fast, and you didn't say anything about budgets
HyperDrive4 5.25" Bay, ATA133 UDMA6 bus, IDE/PATA and SATA connectors onboard. Upto x8 ECC DIMMs

[wellmad]

Thanks for the advice guys, you're right I should have included some details about budget. I'd love to go with one of the actual SSD drives, but at £200+ for a 32Gb drive it's a little out of my range

The reason for making my own would be to save money really...When I put my new system together I went with a SATA2 drive because the interface is faster, however there is some kind of limitation that says no matter how fast the drive is there is a physical limitation as to the speed of data transfer, making SATA2 no faster at all than SATA1 or indeed IDE and that really the only benefit of SATA is smaller cables (and maybe hotplugging with SATA2)...I think maybe faster spin speed is the only way to have faster drive access but I wondered if flash cards would be even faster than say a 10'000 rpm drive..?

@legacy1: the intel RAID chip, would that be on the PCI raid card or the mobo? I have a P5K Deluxe so not sure what the RAID chip on that is...

@Funkster: there are definately some flash cards that windows sees as fixed disks instead of removable storage, guess I'll have to research them more but they are out there

I just don't know enough about HDDs to make an informed descision

[this_is_gav]

The reason for making my own would be to save money really...When I put my new system together I went with a SATA2 drive because the interface is faster, however there is some kind of limitation that says no matter how fast the drive is there is a physical limitation as to the speed of data transfer, making SATA2 no faster at all than SATA1 or indeed IDE and that really the only benefit of SATA is smaller cables (and maybe hotplugging with SATA2)...I think maybe faster spin speed is the only way to have faster drive access but I wondered if flash cards would be even faster than say a 10'000 rpm drive..?

Depends entirely on use. A Raptors transfer rate is faster than 2 of these by the looks of it (going off of the review numbers), but has much higher latencies. For an OS I guess a couple of these will be faster, but it's so uncommon and by the sounds of it, cluttered, that if you came across any problems, you'd be stuck solving them yourself. There must be other reasons why this hasn't be adopted by enthusiasts too. Can't wait until SSD becomes affordable and standard though. The 1 major bottleneck in PCs will be all-but-eradicated (though for data drives I assume the hard drive will stay as king for a good decade yet).

Keep in mind the drive they had it up against was very, very slow in the areas in which the flash drives would be strongest too (it had some rather exaggerated seek times by the looks of it). It almost looks like a 5400rpm 2.5" drive, even they are faster than the drive they apparently put it up against, a 250gb WD.

[wellmad]

Use would just literally be to make OS boot quicker and apps luanch quicker. Would be using it as a total HDD repalcement...At the moment, Windows takes close to 2 minutes to boot, which is practically the same as my old, 3yr old system that I used to have, which to me is a disappointment...

Yeah, I guess if making an SSD was so cheap and gave kick ass speeds then everyone would be doing it!

Maybe I should just stripe a couple of 32Gb 10'000 rpm drives for best possible speeds as sugested by LegacyOne

[this_is_gav]

For a boot drive that's not really going to make that much difference (I've got 2 Raptors in a RAID0 both at home and work). There is some difference, but it's not much. Where RAID0 is at it's best is sustained transfers, and general use is quite hard to measure. I certainly don't think you could see a notable difference in boot time anyway without resorting to benchmarks. They do make a difference in everyday use, but only in specific uses, and you have to question the value. If you do want an increase in hard drive speed you'd be better served with a single 76gb Raptor in my opinion - seek times would be exactly the same as in a RAID0 set up and you'd have half the chance of an array failure.

The small Raptors are 36GB anyway [/pedantic]

[LegacyOne]

@legacy1: the intel RAID chip, would that be on the PCI raid card or the mobo? I have a P5K Deluxe so not sure what the RAID chip on that is...

Yep mobo RAID and your mobo supports RAID if you choose to RAID flash or Raptor.

[wellmad]

ok thanks for the info guys

[Funkstar]

@Funkster: there are definately some flash cards that windows sees as fixed disks instead of removable storage, guess I'll have to research them more but they are out there

Yes there are, but they are not the fastest of cards.

£200 for 32GB is actually pretty good. Especailly when you consider the price of even 4x 4GB cards, 4x CF-to-IDE/SATA adapters and a RAID controller (if you aren't using the motherboard).

SSDs are cheaper per GB and have known performance characteristics. There is a huge question mark over using FLASH cards to do the same thing.

[wellmad]

true, £200 is good, but still way more than I can justify...I was kind of hoping to put one together cheaply using ebay and raw determination..!

[Funkstar]

Well, good luck on that front.

You do know why memory cards are so cheap on eBay don't you? Most of them are fakes

And finding cards that can be used as fixed disks won't be easy i don't think.

I was going to do this with a couple of 4GB SanDisk Extreme IV cards and a couple of these. But then decided not to bother as it probably wouldn't work and would be really expensive even compaired to an SSD

[scombo]

hi guys.

I'm in the process of trying to do the same thing. I'm replacing a laptop's internal 1.8" HDD with a couple of compact flash cards (not RAID). Should be lower power, noise free, cooler and faster! Not to mention more rugged and with geek kudos.

2GB Transcend 266x cards = £17 (just to prove the concept), then 8GB 266x = £90-ish, or £80-ish for an a-data card. Adapter=£7 (ebay from Hong Kong).

Just on some of the other comments made:

The THG article was interesting and not that inaccurate in my view.

The single HDD's seek time of 15ms is normal for a 7200RPM disk (remember this will be average seek in a benchmark - typically for 7200 HDD's this is between 12.5-16ms). 10000RPM disks can get down as low as 8ms but they're still a lot slower than 0.01-0.1ms for flash devices.

Also remember that RAID doesn't improve seek performance (only transfer rates) and as previously stated (I can confirm from my own home & work setups), there is little obvious difference between using 1 or 2 striped Raptors. BUT going from a "bog" disk to a raptor makes a lot of difference, I'm guessing from the lower seek times for file loading.

So, back to flash. With the 266x cards offering UDMA4 and relatively good transfer rates (45MB/s is nothing like a Seagate 7200.11's 100MB/s, I grant you) and vastly superior seek times I'm hopeful that I'll have a neat little laptop in a bit.

-Stuart

[Funkstar]

Two problems i can see you having.

1) the 2GB Transcend cards are unlikely to support fixed disk installations

2) if they do then thats a bonus, but then, will the 8GB disks support fixed disk installations?

It you are going to install linux on your laptop then i'm pretty sure you can force it to install and run. Windows on the other hand...

[mikerr]

On the cheap?
Not RAID, but I did this years ago on my SSD win98 laptop.

CF-IDE HDD style adaptor and 128Mb CF card
(I know, but it was large at the time!).

Been working fine as a silent wifi web pad all this time,
used daily,and no sign of it "wearing out".

At the same time I put that installation on an IDE ZIP cartridge
-was tough to get it to run when it came up as A: drive,
but that was dog slow, and wore the ZIP disk out within a week of casual use

[Agent]

the dificult part is getting fast memory cards that don't identify themselfs as removable storage.

The current speed king is the SanDisk Extreme IV Ducati edition, but windows will only see them as removable storage.

You could try them on a RAID card, it may let you use them as a fixed disk.

You do get 'industrial' cards that appear as a regular drive, but they are more expensive and not as fast.

Two problems i can see you having.

1) the 2GB Transcend cards are unlikely to support fixed disk installations

2) if they do then thats a bonus, but then, will the 8GB disks support fixed disk installations?

It you are going to install linux on your laptop then i'm pretty sure you can force it to install and run. Windows on the other hand...

You've got me well confused here mate
Compact Flash has a built in IDE controller, thus will appear as a removable hard disk to any device its plugged into. There is technically no difference that the machine should see between a IDE hard disk, and a CF card with an IDE adaptor. The IDE adaptor simply maps the pinout of the CF card to the IDE port - there is no conversion on the adaptor done.

USB is a different story - Most (all?) will appear as removable storage due to the controller chip that is used to go from USB->IDE. Remember, IDE does not support hot-swapping, so plugging an CF card in over USB would not work without this arrangement, thus has to use the 'removable' method.
A secondary reason is due to multi card readers - It makes it much easier to manage multiple cards in one reader over USB using this method.

I've never heard of "fixed disk installations" on a CF card?
Edit - see below