Re: [zfs-discuss] Which is better for root ZFS: mlc or slc SSD?
Adam Leventhal wrote: For a root device it doesn't matter that much. You're not going to be writing to the device at a high data rate so write/erase cycles don't factor much (MLC can sustain about a factor of 10 more). With MLC you'll get 2-4x the capacity for the same price, but again that doesn't matter much for a root device. Performance is typically a bit better with SLC -- especially on the write side -- but it's not such a huge difference. The reason you'd use a flash SSD for a boot device is power (with maybe a dash of performance), and either SLC or MLC will do just fine. Or available physical space in the case. For example a home server or small consumer NAS appliance where you want to maximize the space available for the user data ZFS pool and keep the OS in a completely separate pool but don't have the space for even a 2.5 drive. This is exactly the situation have have and I'm planning on migrating the OS to a consumer SSD (A San Disk Extreme III) via an IDE/CF adaptor, thus keeping OS and data pools separate. -- Darren J Moffat ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Which is better for root ZFS: mlc or slc SSD?
For a root device it doesn't matter that much. You're not going to be writing to the device at a high data rate so write/erase cycles don't factor much (MLC can sustain about a factor of 10 more). With MLC you'll get 2-4x the capacity for the same price, but again that doesn't matter much for a root device. Performance is typically a bit better with SLC -- especially on the write side -- but it's not such a huge difference. The reason you'd use a flash SSD for a boot device is power (with maybe a dash of performance), and either SLC or MLC will do just fine. Adam On Sep 24, 2008, at 11:41 AM, Erik Trimble wrote: I was under the impression that MLC is the preferred type of SSD, but I want to prevent myself from having a think-o. I'm looking to get (2) SSD to use as my boot drive. It looks like I can get 32GB SSDs composed of either SLC or MLC for roughly equal pricing. Which would be the better technology? (I'll worry about rated access times/etc of the drives, I'm just wondering about general tech for an OS boot drive usage...) -- Erik Trimble Java System Support Mailstop: usca22-123 Phone: x17195 Santa Clara, CA Timezone: US/Pacific (GMT-0800) ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss -- Adam Leventhal, Fishworkshttp://blogs.sun.com/ahl ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] Which is better for root ZFS: mlc or slc SSD?
I was under the impression that MLC is the preferred type of SSD, but I want to prevent myself from having a think-o. I'm looking to get (2) SSD to use as my boot drive. It looks like I can get 32GB SSDs composed of either SLC or MLC for roughly equal pricing. Which would be the better technology? (I'll worry about rated access times/etc of the drives, I'm just wondering about general tech for an OS boot drive usage...) -- Erik Trimble Java System Support Mailstop: usca22-123 Phone: x17195 Santa Clara, CA Timezone: US/Pacific (GMT-0800) ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Which is better for root ZFS: mlc or slc SSD?
Erik Trimble wrote: I was under the impression that MLC is the preferred type of SSD, but I want to prevent myself from having a think-o. I'm looking to get (2) SSD to use as my boot drive. It looks like I can get 32GB SSDs composed of either SLC or MLC for roughly equal pricing. Which would be the better technology? (I'll worry about rated access times/etc of the drives, I'm just wondering about general tech for an OS boot drive usage...) SLC is faster and typically more expensive. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Which is better for root ZFS: mlc or slc SSD?
On Wed, 24 Sep 2008, Erik Trimble wrote: I was under the impression that MLC is the preferred type of SSD, but I want to prevent myself from having a think-o. SLC = Single level MLC = Multi level Since the SLC stores only a binary value rather than several possible encoded values it becomes more reliable but stores less data per cell. Bob == Bob Friesenhahn [EMAIL PROTECTED], http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer,http://www.GraphicsMagick.org/ ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Which is better for root ZFS: mlc or slc SSD?
On Wed, 24 Sep 2008, Erik Trimble wrote: I was under the impression that MLC is the preferred type of SSD, but I want to prevent myself from having a think-o. Depends on what one prefers, I guess. :-) SLC is prefered for performance reasons, MLC tends to be cheaper. I installed an SLC SSD in my Ferrari 3400. It was SIGNIFICANTLY faster than the 7200RPM spinning rust it replaced (which was no slouch itself). times/etc of the drives, I'm just wondering about general tech for an OS boot drive usage...) FWIW, I'd say go with SLC. -- Rich Teer, SCSA, SCNA, SCSECA CEO, My Online Home Inventory URLs: http://www.rite-group.com/rich http://www.linkedin.com/in/richteer http://www.myonlinehomeinventory.com ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Which is better for root ZFS: mlc or slc SSD?
On Wed, Sep 24, 2008 at 1:41 PM, Erik Trimble [EMAIL PROTECTED] wrote: I was under the impression that MLC is the preferred type of SSD, but I want to prevent myself from having a think-o. I'm looking to get (2) SSD to use as my boot drive. It looks like I can get 32GB SSDs composed of either SLC or MLC for roughly equal pricing. Which would be the better technology? (I'll worry about rated access times/etc of the drives, I'm just wondering about general tech for an OS boot drive usage...) Depends on the MFG. The new Intel MLC's have proven to be as fast if not faster than the SLC's, but they also cost just as much. If they brought the price down, I'd say MLC all the way. All other things being equal though, SLC. --Tim ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Which is better for root ZFS: mlc or slc SSD?
On Wed, Sep 24, 2008 at 1:41 PM, Erik Trimble [EMAIL PROTECTED] wrote: I was under the impression that MLC is the preferred type of SSD, but I want to prevent myself from having a think-o. MLC - description as to why can be found in http://mags.acm.org/communications/200807/ See Flash Storage Memory by Adam Leventhal, page 47. -- Mike Gerdts http://mgerdts.blogspot.com/ ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Which is better for root ZFS: mlc or slc SSD?
Tim wrote: On Wed, Sep 24, 2008 at 1:41 PM, Erik Trimble [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: I was under the impression that MLC is the preferred type of SSD, but I want to prevent myself from having a think-o. I'm looking to get (2) SSD to use as my boot drive. It looks like I can get 32GB SSDs composed of either SLC or MLC for roughly equal pricing. Which would be the better technology? (I'll worry about rated access times/etc of the drives, I'm just wondering about general tech for an OS boot drive usage...) Depends on the MFG. The new Intel MLC's have proven to be as fast if not faster than the SLC's, That is not comparing apples to apples. The new Intel MLCs take the slower, lower cost MLC chips, and put them in parallel channels connected to an internal controller chip (think of RAID striping). That way, they get large aggregate speeds for less total cost. Other vendors will start to follow this idea. But if you just take a raw chip in one channel, SLC is faster. And, in the end, yes, the new intel SSDs are very nice. but they also cost just as much. If they brought the price down, I'd say MLC all the way. All other things being equal though, SLC. --Tim ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Which is better for root ZFS: mlc or slc SSD?
In general, I think SLC is better, but there are a number of brand-new MLC devices on the market that are really fast; until a new generation of SLC devices show up, the MLC drives kind of win by default. Intel's supposed to have a SLC drive showing up early next year that has similar read performance to their new MLC device, but with 2x the write speed, but that's at least 3 months out. Scott On Wed, Sep 24, 2008 at 12:16 PM, Neal Pollack [EMAIL PROTECTED] wrote: Tim wrote: On Wed, Sep 24, 2008 at 1:41 PM, Erik Trimble [EMAIL PROTECTED] wrote: I was under the impression that MLC is the preferred type of SSD, but I want to prevent myself from having a think-o. I'm looking to get (2) SSD to use as my boot drive. It looks like I can get 32GB SSDs composed of either SLC or MLC for roughly equal pricing. Which would be the better technology? (I'll worry about rated access times/etc of the drives, I'm just wondering about general tech for an OS boot drive usage...) Depends on the MFG. The new Intel MLC's have proven to be as fast if not faster than the SLC's, That is not comparing apples to apples. The new Intel MLCs take the slower, lower cost MLC chips, and put them in parallel channels connected to an internal controller chip (think of RAID striping). That way, they get large aggregate speeds for less total cost. Other vendors will start to follow this idea. But if you just take a raw chip in one channel, SLC is faster. And, in the end, yes, the new intel SSDs are very nice. but they also cost just as much. If they brought the price down, I'd say MLC all the way. All other things being equal though, SLC. --Tim ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
