Q: Replace Hard Drive with SSD
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Oct 3, 2015 12:36 PMby R.K.Orion,SSDs haven't been around long enough to see if they'd be permanent backup storage. I don't know why anyone would use one for a backup when you can buy a 2TB backup drive for about 100 bucks. It's designed for that and most spin down to idle when not in use so the drive isn't experiencing wear and tear.
I have no idea how long an SSD will keep its stored data in a static state for a long period of time, and I don't think anyone else does either.
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Oct 9, 2015 11:35 AMby CaptH,Unless someone is using a very high speed interface, using an SSD for backup makes little sense. On many USB and Firewire interfaces the interface itself will bottleneck the use of the drive as an external. I used an SSD in a USB 2.0 enclosure to beta test El Capitan and it might as well have just been a hard drive. I know USB 3.0 is faster, but the enclosure I had sitting around was 2.0, so that's what got used.
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Oct 13, 2015 11:44 AMby MrWilliams201,When I was fooling around with El Capitan Beta I created a Fusion drive out of a small SSD and an old HDD. The SSD was in a USB 2.0 enclosure and the HDD was in a Firewire enclosure. I wanted to use the beta without risking any regular drives.
In any case, the Fusion setup via USB booted a lot faster than a regular hard drive. Oddly, when the SSD is configured as just a standalone drive and used in the USB enclosure, it's about half as fast and bottlenecks just as stated. I have to wonder if the Fusion setup isn't quickly loading an cacheing something to make it seem faster.
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Nov 10, 2015 11:06 AMby CaptH,MrWilliams201 wrote:
When I was fooling around with El Capitan Beta I created a Fusion drive out of a small SSD and an old HDD. The SSD was in a USB 2.0 enclosure and the HDD was in a Firewire enclosure. I wanted to use the beta without risking any regular drives.
In any case, the Fusion setup via USB booted a lot faster than a regular hard drive. Oddly, when the SSD is configured as just a standalone drive and used in the USB enclosure, it's about half as fast and bottlenecks just as stated. I have to wonder if the Fusion setup isn't quickly loading an cacheing something to make it seem faster.
It's probably the way the thing uses the unified buffer cache.
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Nov 11, 2015 11:01 AMby R.K.Orion,CaptH wrote:
MrWilliams201 wrote:
When I was fooling around with El Capitan Beta I created a Fusion drive out of a small SSD and an old HDD. The SSD was in a USB 2.0 enclosure and the HDD was in a Firewire enclosure. I wanted to use the beta without risking any regular drives.
In any case, the Fusion setup via USB booted a lot faster than a regular hard drive. Oddly, when the SSD is configured as just a standalone drive and used in the USB enclosure, it's about half as fast and bottlenecks just as stated. I have to wonder if the Fusion setup isn't quickly loading an cacheing something to make it seem faster.
It's probably the way the thing uses the unified buffer cache.
On Mavericks I've noticed that at startup the base memory is a few hundred megabytes higher than it is without a Fusion drive, so the unified buffer cache theory might make sense, but the overhead isn't too impressive IMHO.
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Dec 12, 2015 11:36 AMby CaptH,MrWilliams201 wrote:
Thanks. The info I'm seeing on that on the web is pretty dated. Is it still in use in the newer OSes like Yosemite and El Capitan?
To the best of my knowledge, yes. I don't know why it would be eliminated. It increases performance and cuts down on energy consumption.
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Dec 31, 2015 10:40 AMby ZV137,Additionally more stuff is being stored in RAM rather than disk. Compressed memory is a good example. A file that used to be written to the drive as a temp file is now first compressed and held in memory and only written to the drive if needed (running out of memory). The write process on both HDDs and SSDs is slow compared to internal RAM I/O plus it supposedly helps energy consumption on laptops. That's one example, but I get the impression a lot more applications and/or kernel functionality is RAM resident rather than being paged out.
