Much has been made lately about the trend toward solid-state drives. Now a new Intel technology, code-named Braidwood, may delay that trend, blending the performance of solid-state drives with the economy of old-style hard drives.
Braidwood--like its predecessor, Intel's Turbo Memory technology (formerly code-named Robson)--is basically a solid-state cache for all the disks in the system.
I heard about Braidwood earlier this summer on CNET (see "Intel 'Braidwood' chip targets snappier software" by Brooke Crothers). But I shrugged it off, assuming it would be no better than Turbo Memory, which left a bad taste in the mouth of many PC makers, end users, and Microsoft execs. Turbo Memory (and Turbo Memory 2.0) wasn't cheap, and it definitely wasn't worth the cost. The PC industry operates on such slim margins that every dollar's worth of hardware has to earn its keep--and Robson didn't.
But then I read an EE Times article this week by Mark LePedus describing a new report from Jim Handy of analyst firm Objective Analysis.
The 62-page report is titled "Intel's Braidwood: Death to SSDs?"
Handy's report argues persuasively that Braidwood might actually be worthwhile, and that got my attention. I've known him a long time, and he's a very good analyst--he's been covering memory and caching technology a lot longer than I have. He wrote one of the standard references for computer system architects, "The Cache Memory Book."
So I sent Handy a note, and he sent me a copy of the report. And now that I've read it, I'm inclined to agree with his conclusions, assuming the information he's obtained about Braidwood is accurate. It does seem reasonable, at least.
The first thing to understand is why flash memory can be a good disk cache. This boils down to its much faster access times: microseconds, not milliseconds. Flash can actually take much longer to write than a hard disk. But for reads, it's really quick. So if you can be smart about putting the right hard-disk data in the cache, especially by choosing the right time to do those write operations, you can save huge amounts of time on future disk reads.
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