Hybrid HDDs... Performance?

[zerogear]

Is there really that much of a performance increase? Or is it only just to aid the Windows Vista 'ReadyBoost' feature?

 

[Goi]

NAND flash has access times that are an order of magnitude lower than rotational magnetic HDDs, and competitive sequential transfer rates, so it will help in stuff like booting up and application loading. Basically it makes stuff more responsive. I'm not sure how it ties in with Microsoft's ReadyBoost or Intel's Robson. Too many new terms out there, it's getting me confused 😛

 

[oldman420]

from wiki
drawbacks to the use of hybrid drives:

Increased seek time for non-cached data: If the data being accessed is not in the cache and the drive has spun down, seek time will be greatly increased since the platters will need to spin up again.
Increased Cost: Flash memory chips are much more expensive per-gigabyte than comparably-sized traditional hard drives.
Increased frequency of spin-up: a hard drive, once spinning, suffers almost no wear. A significant proportion of wear arises during the spin-up and spin-down processes. A hybrid drive requires spin-up and spin-down more often than a normal hard drive, which is often spinning without a break.
Disk spinup is also the time when HDD uses the most power.
Two other potential issues arise with regards to flash memory:

Lower recoverability - After failure any data in flash memory is completely lost as the cell is destroyed, while if normal HDD suffers mechanical failure the data is often recoverable using expert help. The amount of data lost if the cache of a hybrid drive is lost may be significant due to the cache size compared to the cache on non-hybrid drives.

I would wait and get a solid state drive.

 

[zerogear]

Well, I'm just weighing the differences, since I am thinking about investing in a 10k RPM drive. Seems like increased seek time would technically slow the computer down if you ran many applications at the same time, while at the same time increasing costs and lowering operating life of the device + use more power. Thanks for the info oldman 🙂. Based on that, I think hybrid drives are currently too early to show any benefits

 

[50]

Are these out yet? I need a new hard drive in my laptop and am considering these.

 

[pm]

from wiki

Which wiki?

drawbacks to the use of hybrid drives:
Increased seek time for non-cached data: If the data being accessed is not in the cache and the drive has spun down, seek time will be greatly increased since the platters will need to spin up again.

This is true of non-hybrid drives as well; in either case, the seek time when the drive is spun down will be horrible. This isn't an issue with hybrid drives though - all hard drives have this issue. And if you are trying to save power, then you'll want to spin down a normal hard disk too. The thing is, you have the option of spinning down a hybrid and still being able to write to it - you don't have to, but you can. This can only be considered an advantage. Besides which, this is an issue only in notebooks anyway. I doubt anyone will set the low-power settings to max on a desktop drive.

Increased Cost: Flash memory chips are much more expensive per-gigabyte than comparably-sized traditional hard drives.

Yes, but the hybrid drives that I have seen only use 256MB. 256MB should only add a little to the cost.

Increased frequency of spin-up: a hard drive, once spinning, suffers almost no wear. A significant proportion of wear arises during the spin-up and spin-down processes. A hybrid drive requires spin-up and spin-down more often than a normal hard drive, which is often spinning without a break.

Again, you don't need to unless it's being used in a low-power application - in which case, you would want to spin down a "normal" drive too.

Disk spinup is also the time when HDD uses the most power.

Which is also true of non-hybrid drives.

Two other potential issues arise with regards to flash memory:
Lower recoverability - After failure any data in flash memory is completely lost as the cell is destroyed, while if normal HDD suffers mechanical failure the data is often recoverable using expert help. The amount of data lost if the cache of a hybrid drive is lost may be significant due to the cache size compared to the cache on non-hybrid drives.

When not in a low-power spin-down mode, all write data is mirrored to both the Flash and the magnetic disk - and, given that the speed of writes on magnetic disks is - the last time that I looked - better than writing NAND Flash, there shouldn't be this issue at all because the data that we are worried about will be on the hard disk first. Besides, hybrid disks that I have seen use less RAM cache (8MB vs. 16MB) so this issue is even less of a problem. If there's an issue of trying to get the data off the Flash - flash is even easier to read than a hard disk in a lab situation. I've made my own Flash reader circuit - it's not that hard at all (relatively speaking). But I've never tried to recover data off of a magnetic disk that is dead - that would require a clean room and experience and equipment.

http://www.samsung.com/Products/HardDis...lashon_HM16HJI.asp?page=Specifications

To the best of my knowledge, you can't buy them yet.

 

[Jiggz]

I'll take an hybrid over platter drive anytime or better yet a full SSD drive.