Power pushing 2.5" drives to tipping point

Power pushing 2.5" drives to tipping point

Summary: Remember 5.25" hard drives?I remember 18" hard drives.

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TOPICS: Data Centers
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Remember 5.25" hard drives? I remember 18" hard drives. Then 14", 9" and 8", 5.25" and now 3.5". The secular trend is clear: disk drives shrink. So when do we make the leap to 2.5" drives in the data center.

Traditionally, the jump started when the smaller form factor could hold a the operating system, applications and some user data. Obviously 2.5" drives passed that point several years ago and still no migration. Why?

Storage arrays are one reason. Arrays have made disks simple bit buckets instead of a design center for new systems. The shrinking number of I/Os per GB is hidden by cached controllers. Density per square foot is increased by drive capacity growth. And you may recall that the only 3.5" form factor available today is what used to be called Low-Profile, which is thinner than Half-Height. Thinner drives mean greater density.

Five out of five analysts agree: power is a problem On an analyst panel at Cisco yesterday, we got into power issues for today's data centers. How to fix? Power distribution, cooler CPUs, containerized data centers all got some play. To me though, all that is nibbling around the edges of the problem. Data capacity is exploding, so what about disk drives?

The new quad-core Xeon CPU draws less than 50 watts. Stick it in a server with 12 drives and the storage power draw drowns it.

Optimized for low power consumption Vendor power stats are about as useful as vendor MTBFs, given all the unspecified assumptions that go into them. Yet the peak numbers are suggestive. Enterprise drives, FC, SCSI and 10k SATA drives, are in the 12-15 watt area. 2.5" notebook drives are 2-3 watts. And don't forget that for every watt consumed, another 0.4 watts is needed for cooling, not to mention power supply and distribution losses.

GB per watt? Lower in 2.5" because the drives are slower and enterprise drives have similar capacities to support their higher speeds.

Cost per GB crossover Over at the market-driven prediction site Storage Markets they've been looking at the 10k 2.5" enterprise drive market. Last I looked they predicted that the cost per GB of high-end 2.5" drives would equal 3.5" drives some time this year. But Seagate's 10k 2.5" drives are power hogs, spec'd at about 8 watts peak. They'll give you a tiny and speedy array, but not a particularly power-efficient one.

The race is not always to the swift Array vendors like fast drives because they carry higher margins, but drive speed is just one way to achieve array performance, and not a very good one at that. Caching and striping are much more important, while big commodity storage systems - think Google and Amazon - use file replication. Even though their heads are slower, 2.5" drives pack many more heads into a given cubic volume, giving array engineers more degrees of freedom in crafting solutions.

Nor riches to the wise I have no doubt that engineers at Google, Amazon, Yahoo and MSN are calculating when it will make sense to move to 2.5" drives. Once they start the economics will complete the job in less than five years. Average data center floor space may even start to shrink, given the much greater space efficiency of 2.5" drives.

But time and chance happen to all men The economics of high-volume manufacturing are such that once the switch begins, the advantages will be almost irresistible. What triggers the switch is less clear today than in the past. There can be no doubt that power concerns will play a much bigger role than in past form factor migrations.

Comments welcome, of course.

Topic: Data Centers

About

Robin Harris has been a computer buff for over 35 years and selling and marketing data storage for over 30 years in companies large and small.

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7 comments
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  • We use them now.

    All new HP ProLiant servers we order have the 2.5" 10K SAS drives. Sure, they are not as power efficient as the notebook drives, but they are much quicker and still only use half the power of the 3.5" SCSI drives.
    Atoyot
  • Poorly worded article

    2.5" drives are ALREADY in the enterprise. I have 9 servers using the 2.5" SAS drives from Seagate. Dell is using these drives in a lot of servers, both 8th and 9th generation.

    So I guess you're wondering when notebook drives, meaning IDE or SATA will be implemented? And doesn't that make your article less about size and more about format? 3.5" IDE and SATA drives are also in the enterprise, so it's just a matter of time. Since most pundits predict a sharp decline in desktop sales vs laptops in the near years, I suppose the 3.5" consumer drive will also be on the decline.
    In general, I trust 2.5" consumer grade drives less that 3.5" for reliability. But a lot of that is based on the performance in laptops, which are subjected to much higer abuse than enterprise grade, rack mounted equipment. As long as we're in RAID mode so a drive failure is a non-critical event, I'm fairly comfortable.
    shraven
  • Drives Obsolete?

    With the release of 32 GB flash memory cards this spring and 64 GB cards in the pipeline (and presumably the standard multiples of 2 beyond that), drives are destined for the waste bin of computing history. Flash drives use less electricity, generate less heat, and have no moving parts. Surely when the price of these drives matches that of hard disks, hard disks will go the way of the dodo.
    brilang
    • not just 32gb cf

      just yesterday, 030307, i was browsing and found a 160gb ssd sata and ata (yes, that's not a typo, 160gb), obviously lower power, faster access, cooler device than hdd 2.5". and w/ hdd-usb adapter, we're still talking about usb conectivity. i'm already using an 8gb version of this, and have also seen 1.8" versions as well. still sort of cost prohibitive, ~$400 for 4gb, but that's sure to drop rapidly as laptop manufacturers start to use these instead of hdd, something i've also read about recently. the problem w/ large cf storage, is it is still infrequent to find a fast, bootable interface. the adapters are as slow or slower than my old 6 gb 5400rpm ata66 laptop drive. additionally, if seen many ide and sata direct socket ssd modules in 2,4,6, 8, & 16gb variations that undoubtedly will become more prolific in the coming months/years.
      inertman@...
  • It'll happen when...

    SSD HDDs become more widespread and more available, but then by that point the space issue would rear its head again, since with the memory chips rather than platters HDDs can assume just about any shape to fit the avaliable space/format.

    I myself can hardly wait for this so I can upgrade the "drive" in my laptop the speed gains that should result.
    jbjerome
  • I doubt it will ever happen. Here's why...

    The new Solid State Disk hard drives are the same physical size as 2.5" drives so they are backward compatible. Sandisk, TDK, Adtron has them in production and so do a few others in this industry. They run at good speeds although they aren't all as fast as the top end hard drives that are out today. This technology is extremely new, so it won't be that long before you're putting it in your laptop to increase battery life and in your blade server to decrease noise.
    No noise, extremely low power, no spin up to be ready, no seek time overhead to speak of, much less heat as compared to HDs.
    There are disadvantages, like price. Similar to what the 2.5" drive was when it first was being distributed. SSD's are still fairly expensive. Capacity is also an issue with most vendors originally coming out with 32gb drives and now Adtron has a 160gb. Isn't that on the top end (or close to it) of capacity for 2.5's?
    2.5" and 3.5" blades of SSD's will be our future. Why mess with the old mechanical drives for that much longer. It's future is quite limited.
    Jake
    jakesty
    • not only 2.5"

      i have also seen ssd modules that are not either 3.5' or 2.5', but a module that plugs directly into the sata or ide plug on the mobo, no high than the cpu fan/heatsink. samsung has many of these. they are also not as fast as current hdd, but are not fixed to the sizes that they use. in the case of my micro itx, 2 ata modiles that would not excede the hieght of the daughtrboard will fit w/o the worry about where to mount them,and therefore a smaller case. it's not just about size or volume anymore.
      inertman@...