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Will PCIe Flash Become Common In Laptops, Desktops?
Lucas123 writes "With Apple announcing that it is now using PCIe flash in its MacBook Air and it has plans to offer it in its Mac Pro later this year, some are speculating that the high-speed peripheral interface may become the standard for higher-end consumer laptops and workplace systems. 'It's coming,' said Joseph Unsworth, research vice president for NAND Flash & SSD at Gartner. The Mac Pro with PCIe flash is expected to exceed 1GB/sec throughput, twice the speed of SATA III SSDs. Apple claims the new MacBook Mini got a 45% performance boost from its PCIe flash. AnandTech has the Air clocked in at 800MB/s. Next year, Intel and Plextor are expected to begin shipping PCIe cards based on the new NGFF specification. Plextor's NGFF SSD measures just 22mm by 44mm in size and connects to a computer's motherboard through a PCIe 2.0 x2 interface. Those cards are smaller than today's half-height expansion cards and offer 770MB/s read and 550MB/s write speeds."
From the photos Apple has on their site of the Mac Pro with its cover open, it looks to me like the flash storage used is a "mini PCIe" form-factor. I've already purchased and used an identical looking 480GB flash drive to fit in an HP "Ultrabook" type of portable called the "Spectre XT Pro".
(HP claims the notebook can't be purchased with a drive larger than 256GB, even in a custom build order on their web site, but a technical manual I found clearly showed it took the mini PCIe type of flash drive, so I bought a 480GB from CDW to try it and it worked just fine.)
I've seen a few comments yesterday and today though claiming some of these mini PCIe form-factor SSDs are not *really* following the standards for the PCIe connector? So in effect, they perform with a lot less throughput, the same as any existing SSD drive, except just using that type of physical connector.
Anyone know if there's much truth to such claims .... meaning what Apple is offering here really will be more advanced than current SSD technology, or is this a case where companies like HP have really been using the same stuff for at least the last 1-2 years in select ultraportables?
Why Apple is taking credit for this new trend? Sony new Vaio Pro line has optional 20Gbps PCIe 256/512GB flash storage. I pre ordered one(first vaio in 9 years) simply because of that. Credit where it's due.
Even high IOPS is starting to become meaningless. Here's an Anandtech comparison of top SSDs from two years ago of typical tasks which stressed IOPS. He played it straight for this one page and showed benchmarks in units that matter to people's perception of speed - seconds to complete a task. The result is utterly uninteresting. The HDD is substantially slower. The SSDs are for all practical purposes identical.
But boring graphs are bad for review sites. If the reviews are boring, people won't read them, and the sites lose out on ad revenue. So they invert the metric to make smaller differences appear bigger. Instead of the practical sec/MB, they use the more ephemeral MB/sec. That makes the graphs more interesting and gets people coming back to the sites before buying, instead of just buying some random cheap SSD without really caring about the max speed.
"But sec/MB and MB/sec are the same number! Why should inverting it make a difference?" Because when you invert a metric, the big numbers become small numbers, and the small numbers become big numbers. e.g. Say you have a HDD which can read 100 MB/s, a cheap SSD which can read 200 MB/s, and an expensive SSD which can read 500 MB/s. So in 1 second, the HDD reads 100 MB, the cSSD 200 MB, and eSSD 500 MB. Expressed in MB/s you gain 100 MB/s switching from HDD->cSSD, and a whopping 300 MB/s switching from cSSD->eSSD. Switching from cSSD->eSSD gives you 3x the benefit of switching from HDD->cSSD! So the extra money for the expensive SSD is definitely worth it! Right?
Hold on. Invert to s/MB and say you need to read 1 GB. The HDD takes 10 sec, the cSSD 4 sec, and the eSSD 2 sec. Switching from HDD->cSSD saves you 6 seconds. Switching from cSSD->eSSD only saves you 2 sec. So in terms of time you spend waiting, the HDD->cSSD switch saves you 3x as much time as the cSSD->eSSD switch. The vast majority of your time saved can actually be obtained from the switch to the cheaper SSD. The next step switching to the expensive SSD only gives you a marginal improvement. (Even if you insist on using relative measures of time, the cheap SSD still wins. 10 sec to 4 sec is a 60% reduction in time. 4 sec to 2 sec is only a 50% reduction in time. Or if you want to be a purist, of the 8 sec saved going from 10 sec to 2 sec, the cheap SSD gets you 75% of that speedup, the expensive SSD gives only the remaining 25%)
Unless you're regularly doing tasks where you find yourself twiddling your thumbs for several seconds or minutes waiting for the SSD to finish reading/writing several GB of data, the difference between 600 MB/s and 1.25 GB/s is imperceptible despite being a 2x speedup. Twice as fast as the blink of an eye is still as fast as a blink of an eye to our perception.