Linked by Thom Holwerda on Thu 27th Sep 2012 19:36 UTC
Apple I bought a brand new iMac on Tuesday. I'm pretty sure this will come as a surprise to some, so I figured I might as well offer some background information about this choice - maybe it'll help other people who are also pondering what to buy as their next computer.
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Something important missing
by bowkota on Thu 27th Sep 2012 20:18 UTC
bowkota
Member since:
2011-10-12

I'm guessing (like most iMac buyers) you got it without an SSD and it's a shame. The difference in the experience between an HDD and and SSD is massive nowadays, I could never go back.

Reply Score: 5

lucas_maximus Member since:
2009-08-18

I am running a desktop (mobo from 2005 or 2006, first lot of mobos to support Core 2 duo) with RAID 1 SSDs for the OS (60GBs), and it just another world running SSDs.

Reply Parent Score: 2

ggeldenhuys Member since:
2006-11-13

Yup. I just build my own i7 desktop PC with a 128GB SSD. From GRUB boot menu to fully loaded and functional desktop.... 3.5 seconds. Who needs hibernate! You gotta love Linux+JWM.

Reply Parent Score: 3

RE: Something important missing
by Alfman on Thu 27th Sep 2012 21:10 in reply to "Something important missing"
Alfman Member since:
2011-01-28

bowkota,

Even though SSD's are becoming affordable, I'm not keen on their falling reliability levels. First there was SLC - 1 bit per cell, then MLC with 2 bits per cell (4 voltage levels). Now we're seeing 3 bits per cell (8 distinguishable voltage levels). This produces higher capacity drives for very low manufacturing costs.

Each generation is moving towards ever smaller manufacturing processes: from 100nm in 2007 to 20nm today. This means more cells per area, but also that fewer electrons are available to represent a bit state, and increasing the likelihood of getting stuck electrons.

Combine both of these trends and it spells disaster for reliability. I experienced my own data loss, which is why I've been researching these things.

I looked up the specs for NAND chips used in my device, and they officially only spec 3K program/erase cycles before loosing data integrity!!! This is much lower than the million write cycles we had using 100nm SLC NAND.

3,000 P/E cycles (with 24 bit/ 1,024byte ECC)

http://www.jm-chip.com/en/down/H27UBG8T2A.pdf
(link is down)

http://forums.anandtech.com/showthread.php?t=2144579
(they talk about it here)

Flash devices use smart controllers to distribute the writes across all cells of the NAND chip to alleviate the effects of any individual sector updates on the logical media. This is fine assuming most sectors rarely change. However if you have a data load that routinely rewrites significant portions of the flash disk - then the average cell lifespan will be consumed fairly quickly. Due to the write-distribution algorithm there is a good chance that all NAND pages will reach EOL at approximately the same time, so once data errors are discovered, there are probably more errors that haven't even been discovered yet.

Not saying it's for nobody, but do your research... failure is common. By all means keep backups! ( Ideally not on flash drives ;) )

I've been trying my own hand at performing data recovery off failing flash media, so if anyone does get unrecoverable flash media, I might be able to offer my services ;)

Reply Parent Score: 3

Morgan Member since:
2005-06-29

Regarding SSD reliability: I've always been of the mind that you should run your OS and installed programs on the SSD for the speed gains and keep your data on a traditional HDD to avoid data loss. On GNU/Linux and BSD this is easy; during installation just put your /home on the HDD and you're good to go. On Windows you can point your User folder at a different volume with a few extra steps after installation.

Reply Parent Score: 4

lfeagan Member since:
2006-04-01

The firmware can also greatly help or hinder the reliability of a particular flash chip.

You should always be prepared by keeping regularly backups with one of the many free or commercial backup programs--regardless of using an SSD or a spinny disk.

Reply Parent Score: 1

lucas_maximus Member since:
2009-08-18

I think it is fairly evident that you should have a decent backup plan SSD or not.

This is not new.

Reply Parent Score: 3

bassbeast Member since:
2007-11-11

Good luck on recovery as I've tried my hand at it too and with SSDs it seems like the controller goes bad more times than not so you are just boned. this is one of the reasons i always push my "backup backup backup" mantra upon customers, especially my gamer early adopters, as its just too easy to get bit by new tech failing.

But this is why I say there are places where SSDs make sense and places where it doesn't. If its a mobile and you have a USB drive to backup important data? Makes sense as no moving parts and you can easily slap the drive you pulled from the unit to go SSD into an external case and use it for a backup. Gamers where its just the OS and a few games? Again makes sense, they can have a disc image and if it dies just use a HDD until your replacement arrives. Businesses or anything that is mission critical? Does NOT make sense, the risk of failure and the cost of downtime makes it not worth the extra speed.

So I'd say SSDs are like any other tool in that you have to know where its a good fit and where its not. I'll personally switch my HDD in my netbook for an SSD after the first of the year, the extra battery life and faster boot times will make it worth the hassle and risk. On my desktop where I only put the system to sleep? Not gonna bother because with 8Gb of RAM for Superfetch even with my OS drive being a 5400RPM EcoDrive it just wouldn't be worth the increased risk.

Reply Parent Score: 2

RE: Something important missing
by graig on Sat 29th Sep 2012 14:47 in reply to "Something important missing"
graig Member since:
2010-09-18

I'm guessing (like most iMac buyers) you got it without an SSD and it's a shame. The difference in the experience between an HDD and and SSD is massive nowadays, I could never go back.


i just got the macbookpro retina machine. and you are right.. SSDs are awesome. the only downside is the getting less space and paying more money.

Reply Parent Score: 2

RE: Something important missing
by aliquis on Sat 29th Sep 2012 17:49 in reply to "Something important missing"
aliquis Member since:
2005-07-23

The test I've seen seem to suggest an SSD cache is enough and give most of the benefits.

Reply Parent Score: 2