Feeds

Intel refutes SSD slowdown accusation

It's not the X-25-emmental

High performance access to file storage

Intel has rejected a reported finding that its clever controller algorithms that deliver terrific write I/O performance on its X25-M solid state drives actually contributes to them slowing down over time.

The issue is fragmentation. The Intel controller combines many small file writes, smaller than the X25-M's block size, into a single larger one thus avoiding unnecessary block erase/write cycles. To avoid the flash wearing out through repeated writes, its wear-levelling algorithm avoids concentrating writes on particular cells by re-mapping the physical cells into logical ones and progressively moving around the flash cells, such that logical flash cell zero isn't necessarily physical flash cell zero.

The PC Perspective reviewer, trying to duplicate real world use of flash, found that the X25-M's write speed declined substantially over time. He reckoned that Intel's controller algorithms and cell remapping means that a host PC/server O/S cannot see fragmentation on the X25-M and so cannot deal with it; only the controller can, and it doesn't do at all well over a longish period. The drive eventually achieves a kind of steady state fragmentation.

The result is that: "We found that a ‘used’ X25-M will always perform worse than a ‘new’ one, regardless of any adaptive algorithms that may be at play. We also found that in some cases, the drive would drop to significantly below manufacturer specs."

The specc'ed 70MB/s write speed can drop to 25MB/sec or even lower.

Emmental cheese The reviewers tried to use Windows' defragmentation utility to fix this problem, but "running the Windows defragmenter on the X25-M would rapidly Swiss Cheese the crap out of it, defeating the purpose entirely," turning it into the X25-emmental we guess.

(It's worth reading the fairly long review, 'Long-term performance analysis of Intel Mainstream SSDs', in detail to get a better understanding of what the reviewers did.)

Intel says it has not been able to reproduce these results which are, obviously, detrimental to the X25-M's prospects. Its statement said: "In our estimation, the synthetic workloads they use to stress the drive are not reflective of real world use."

It admitted that some slowing of performance should be expected as drives, whether spinning disk or flash memory, get full, but nothing like the PC Perspective finding. Intel is talking to the reviewers to understand their methodology and see if a firmware update for the X25-M will be necessary.

Customers won't see the Swiss-cheesing of their X35-Ms unless they use the device heavily. If you are using slowed-down X25-Ms, then completely delete data on the drive to get back most of the lost performance. ®

High performance access to file storage

More from The Register

next story
Seagate brings out 6TB HDD, did not need NO STEENKIN' SHINGLES
Or helium filling either, according to reports
European Court of Justice rips up Data Retention Directive
Rules 'interfering' measure to be 'invalid'
Dropbox defends fantastically badly timed Condoleezza Rice appointment
'Nothing is going to change with Dr. Rice's appointment,' file sharer promises
Cisco reps flog Whiptail's Invicta arrays against EMC and Pure
Storage reseller report reveals who's selling what
Bored with trading oil and gold? Why not flog some CLOUD servers?
Chicago Mercantile Exchange plans cloud spot exchange
Just what could be inside Dropbox's new 'Home For Life'?
Biz apps, messaging, photos, email, more storage – sorry, did you think there would be cake?
IT bods: How long does it take YOU to train up on new tech?
I'll leave my arrays to do the hard work, if you don't mind
Amazon reveals its Google-killing 'R3' server instances
A mega-memory instance that never forgets
prev story

Whitepapers

Mainstay ROI - Does application security pay?
In this whitepaper learn how you and your enterprise might benefit from better software security.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
3 Big data security analytics techniques
Applying these Big Data security analytics techniques can help you make your business safer by detecting attacks early, before significant damage is done.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Mobile application security study
Download this report to see the alarming realities regarding the sheer number of applications vulnerable to attack, as well as the most common and easily addressable vulnerability errors.