Seagate brewing bizarre Flash/Platter chimera

A Greek website is reporting that a combined solid state and spinning disk drive may be on the way from Seagate. The hw box story says the hybrid Momentus XT will combine a 4GB solid state drive (SSD) with a 7200rpm rotating hard disk offering 250, 320 or 500GB of capacity. There will be a 32MB cache, a 3Gbit/s SATA interface …

[Anton Ivanov]

Another miserable Windows Vista failure

Well, Vista was supposed to deliver this. The OS has the best knowledge of which bits of information have been accessed and when and it should be trivial for it to keep a cache and a policy for it. Quite clearly however, it has failed.

What I find more surprising is that Linux, BSD and the like have not done anything around this (IIRC Solaris has, but it is standing as a lonely exemption amids the others).

[LuMan]

Easy.

The spinning disc reads your mind and decides what you want next. It then puts this on the solid-state drive so you can get it quicket when you ask for it.

[Is it me?]

What day is the Greek All Fools Day?

I only ask.

[Hardcastle]

Greek All Fool's Day

Why, that would be any day that has a Y in it, see...

[Anonymous Coward]

Are you sure they limit that to only 1 day a year?

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[G2]

*head scratching*

How would you go about DEFRAGGING such a beast ?

the only way i can think it would work is that the flash will be transparent write-through, like a cache... but since the article says it's not really a cache... this leaves me puzzled.

(the flash part could be accessed independently, like a separate device... but what's the point in that? we have usb for that.)

[Dr. Mouse]

The point...

"the flash part could be accessed independently, like a separate device... but what's the point in that? we have usb for that"

Maybe that it is faster flash, on a faster interface?

IF that was how they did it, the flash benefits from the 300MB/s interface of SATA-II and the RAM Cache, and would work much better than using a USB stick for the data.

[Robin]

Fleetwood Mac

> There's lots of uncertainty here, as is the way with rumours

Exactly. Why complain about lack of information about a product that may not even exist?

[toor]

Spin The Flash Around?

No, no, no. You've got it wrong, their spinning the flash memory around, that way the bits escape even faster.

Paris? Because she's welcome to spin around on my platter any day!

[Anonymous Coward]

4GB? Really?

The main benefit I get from my SSDs is the ability to load the OS and my programs quickly. I assume this is way over 4 GB of data. Maybe 16 or 32 GB is in the right ballpark.

As for how it would be set up, I assume the SSD would act as a write-through cache. Maybe a lazy cache to keep the platters from spinning all the time.

Overall great idea, if it had more flash. I could see myself buying a few of these in the future.

[Teoh Han Hui]

Flash

The flash memory is certainly good for random writes. Maybe it will cache frequently accessed data as well (like Intel Turbo Memory)?

[Cliff]

Boot partition? Swap files?

I could see it finding its place

[Steven Jones]

why not cache?

"and is evidently not a cache - or at least not the front-end cache as the 32MB of RAM does that job."

Gee what a bizarre thing to note. Of course it could be be a cache. One little clue is that 4GB of flash is an awful lot bigger than 32MB of RAM so it can hold over 100x the amount of data. Secondly the flash memory is non-volatile so it can cache the frequently accessed blocks without having to wait until the data has been staged down from the HDD. It could also be used for a fast write cache (as it's NV), although that depends how it is implemented, how clever the controller is and what type of Flash is used. Of course it could be used for a separate segmented high-performance area, but 4GB is hardly enough to hold a full systems image and application executables.

The RAM cache in an HDD is there largely as a track buffer for sequential reads. It rapidly runs out of utility when the data set that is being read is moderately large. A hybrid makes sense if the flash is large enough, fast enough (especially for writes) and the caching algorithm is clever enough.

[Anonymous Coward]

Just Move Along

It's from Seagate. Too little, too late. This is a stop gap measure doomed before it's released. They should concentrate on fully SSD instead of this waste.

[Anonymous Coward]

Sounds good to me...

It'll be a long time before SSD catches up on £ per GB. SSDs are getting cheaper/denser but so are hard drives.

I expect this drive will be under £100, for which you'll get 500GB plus a non-volatile write-through cache like you get with top-end RAID arrays.

[Anonymous Coward]

Sadly misinformed

This is not a new concept or technology - using very large and (relatively) high speed caches in front of slow disk based storage has been around for well over a decade. For an identical implementation to Seagate's but on a larger scale just look at Adaptec's MaxIQ which uses a SSD as cache for spindle-based hard drives.

[Anonymous Coward]

How will it work? How will it be used?

The way I see it is that this will be used as a marketing device. Seagate will charge extra for it, the idiots in PC world will be able to say "It's got 4Gb of SSD" and the muppets will lap it up.

Real techies will have no use for it at all since almost anything you could do with 4Gb of SSD built into a drive you could do better with a separate SSD.

[John 62]

just another step in the memory hierachy?

most likely. I mean how many people do you know who actually use a USB flash drive for readyboost? Why not build it in and make it OS independent?