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Fusion Drive Now Available as Option for Low End 21.5" iMac

SvP said:
if 1 in a 100 harddrives break within 5 years,
2 harddrives will have a chance of 2 in 200 they'll fail in 5 years.

edit: may not be this simple 😛 the two will be as one, therefore if one fails- both fail
Click to expand...

Where did you get that 1% of all hard drives fail within 5 years?
 
SvP said:
if 1 in a 100 harddrives break within 5 years,
2 harddrives will have a chance of 2 in 200 they'll fail in 5 years.

edit: may not be this simple 😛 the two will be as one, therefore if one fails- both fail
Click to expand...

1 * 1 / 100 = 1 / 100

2 * 1 / 100 = 1 / 50

the more drives you add the higher the risk that one will fail. (So, you add in even more and more drives to account for this ... Striped Mirrors, Striped Raids, Striped Raids of Mirrors ....)

🙂
 
hfg said:
Where did you get that 1% of all hard drives fail within 5 years?
Click to expand...

Here is a nice article on the probability of HW failures.
http://www.tomshardware.com/news/google-hard-drives,4347.html

In general, Google's hard drive population saw a failure rate that was increasing with the age of the drive. Within the group of hard drives up to one year old, 1.7% of the devices had to be replaced due to failure. The rate jumps to 8% in year 2 and 8.6% in year 3. The failure rate levels out thereafter, but Google believes that the reliability of drives older than 4 years is influenced more by "the particular models in that vintage than by disk drive aging effects."
Click to expand...
 
little.pm said:
1 * 1 / 100 = 1 / 100

2 * 1 / 100 = 1 / 50

the more drives you add the higher the risk that one will fail. (So, you add in even more and more drives to account for this ... Striped Mirrors, Striped Raids, Striped Raids of Mirrors ....)

🙂
Click to expand...

hmm.. 1/100 that drive a fails,
1/100 that drive b fails,
?/? that both drives fail?
 
gnasher729 said:
As far as I know, 10.8.2 is required. And I have never heard a claim otherwise. For example, to access the Fusion drive inside another Mac in "Target Disk Mode" your Mac needs 10.8.2.
Click to expand...
So, for Target Disk Mode you need 10.8.2.
But has anybody ever even tried to Fusion their disks in 10.7?
 
SvP said:
oh, right, so, that explains it.
Click to expand...

I wrote it a bit earlier in this discussion - check it out. Basic idea is, fussion drive are two drives joined to one, each of them has some probability to fail. Using basic probability theory you find out what it means for fussion drive failure probability - again, check it out few posts earlier.

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little.pm said:
1 * 1 / 100 = 1 / 100

2 * 1 / 100 = 1 / 50

the more drives you add the higher the risk that one will fail. (So, you add in even more and more drives to account for this ... Striped Mirrors, Striped Raids, Striped Raids of Mirrors ....)

🙂
Click to expand...

this isnt right as well, probability does not doubles with two drives..

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SvP said:
hmm.. 1/100 that drive a fails,
1/100 that drive b fails,
?/? that both drives fail?
Click to expand...

it is not both drives fail, but at least one of them fails - so you have to sum up 3 probabilities - P of only HDD A fails, P of only HDD B fails and P both HDDs fail, so in your example it is 1,99/100
 
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inscrewtable said:
Not making something smaller, is not the same thing as making it larger. The 2011 imac did not need to be smaller. Yet.

Do you propose making iMacs smaller and smaller over time without limit?
Click to expand...

Yes, as convenience and portability would allow. It would make it much easier to move an iMac ( which is already a very simple task ) from room to room. Or from your home to the Apple Retail Store. I work at Apple, and one of the largest gripes come from the elderly who do not want to move their iMacs to their car, and then from the parking lot into the store.

It would minimize accidental drops while moving the unit. As long as functionality and appeal is not compromised I don't see an issue with reducing the size and weight of iMacs over time. However, brought up in an earlier post by another user, is the limitation on users to do their own service on iMacs. Compressing the parts in the iMac makes it much more difficult for untrained or inexperienced individuals to do self-service on their machines when the warranty period expires.

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little.pm said:
1 * 1 / 100 = 1 / 100

2 * 1 / 100 = 1 / 50

the more drives you add the higher the risk that one will fail. (So, you add in even more and more drives to account for this ... Striped Mirrors, Striped Raids, Striped Raids of Mirrors ....)

🙂
Click to expand...

I think the failure rate is much higher than 1%. On the tech support side of things, I've spoken to customers who have had to replace their hard drive (*coughSeagatecough*) up to three times in one year. Yes it was covered by the manufacturer warranty, but the customer did lose his own time during the replacement periods not to mention the downtime during replacement.

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SvP said:
i didn't. i said "if".
Click to expand...

My bad, I didn't read your post correctly.
 
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inscrewtable said:
Wouldn't have been more useful and easier to simply provide a link to one of the endless detailed youtube videos?


In fact it would be more useful to inform people that because the SSD and the HDD can be easily 'unfused'. It would be better to have the two drives separate so that at least you could use the paltry bit of SSD space left to dedicate specific things to like perhaps your managed aperture folder, or heavy duty video editing. However it would then be painfully obvious that you are paying $300 for a 128GB SSD.

Because the fusion system fills up the SSD with stuff that won't need to be on it and just leaves a 4gb 'landing zone', for mission critical work. Granted the average consumer who buys a 21" probably couldn't care but, as said earlier, it's a gimmick.
Click to expand...

If you think a YouTube link was necessary why didn't you provide one, instead of making it my responsibility? What you think I should have done is really what you should have done. How do you like them Apples? 😉

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NutsNGum said:
I know both what it is, and how to put one together using terminal. I was curious as to why it didn't come in the base model.
Click to expand...

I never said that you didn't know how to do it. Also, why would you think anyone on MacRumors could answer your question regarding why it wasn't an option from the start. Maybe you should ask Tim Cook? 😉

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iGrip said:
They do not form the sweet spot of Apple's target demographic. They don't buy nearly as much as those who are tech naive and like to spend money on a new system from Apple when they need more power.
Click to expand...

Whether the Apple tech naive outnumber the Apple tech savvy is irrelevant. 😉

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DYER said:
I understand this. But it appears as one volume.
What I was trying to point out was the seamlessness.
I am not an expert when it comes to disk management so I think it would be beyond me to configure a system that keeps frequently used files on the SSD and infrequently used ones on the HD.
Click to expand...

No worries. 🙂
 
jasonefmonk said:
I made myself a Fusion drive in my 2011 13-inch MacBook Pro. I removed the optical drive and used a Western Digital 1TB 5400rpm and a Crucial M4 128GB SSD. It works wonderfully.
Click to expand...

Dude! Don't you know that you have a slow drive with a greater chance of failure! #
 
majkom said:
Take it - probability of failure of each of the disk is independent event (this is fact according to theory of probability).
Click to expand...

This is far from a "fact". Power supply events affect both the spinning hard disk and the solid state hard disk - failures due to power events are not independent.

You also fail to consider that some failures may be software failures in the volume manager layers that implement the concatenated drive. These are failures above and beyond any hardware failure.

But, since of course you have full and recent backups, drive and volume failures aren't an issue.
 
Lancer said:
Just an observation but I checked out the 21.5" in store yesterday and noted the formatted HDD size for the 1Tb was about 999Gb in the 'About this Mac' window. But on my older G5 Tower with 1Tb is about 931Gb, meaning the new HDDs must be using a different method to calculate the actual formatted size. The upside is you gain almost 70Gb, doesn't sound like much with 1Tb but it adds up.

Have they changed the actual HDD size so when formatted it is actually the size advertised?

And no the one I looked at did NOT have 128 Gb SSD making up the difference.
Click to expand...

Yes, Apple changed the way OS X measures the HD. This was done 2 years ago I think?
 
roverma said:
And that is exactly what fusion drive does.... And not on file level, but on block level
Click to expand...

The early descriptions of Apple's implementation describe it as an OS-directed file-level placement technique. Where is it describes as a block-level optimization?
 
Mackan said:
It seems some obvious facts elude you. Before you had to buy high end iMac + Fusion drive. Now you can buy low end iMac + Fusion drive, which is cheaper.

I repeat, you can now buy an iMac + Fusion drive cheaper than before. All because Apple was kind enough to press the button to add the BTO option.

If you haven't seen the pattern already, Apple creates these tiered models for their products to maximize profit. You want the best graphics card? Ok, you need to go all in on the high end 27'', etc. You like that?

What happens when you are forced to buy the higher end model? You pay more. And pay for specs you don't want.

I don't see how it can be explained in a way so that some people here understand. It's not about getting what you pay for. This is a different issue.
Click to expand...

No one is forcing you to pay anything or buy anything. This obvious fact eludes you.

Early adopters got exacted what they paid for. And today, if I paid the same price, I get the same exact item with same specs. So early adopters didn't lose or gain anything new except the ability to enjoy their new computer earlier than other people. Every company is doing whatever possible to maximize profit. It's called a business. This is another obvious fact that eludes you. If you don't like it, don't buy it. No one cares.
 
Kuzbad said:
Wow, what a complete joke and ignorant defending of an indefensible hardware decision. 5400rpm is horrendous and has been for many years. I even replaced the stock disk is my PowerBook g4 with a 7200rpm disk because even 7 years ago 5400 rpm disks were awful. I'm amazed anyone can use a MBP/iMac/mini with stock disk. They're so painful to use.

7200...10000...15000rpm 2.5" drives are easily and readily available (and have been common and cheaply available outside of the Mac world for many years).

http://www.newegg.com/Laptop-Hard-Drives/SubCategory/ID-380
Click to expand...


So your idea of "commonly and cheaply" available 1TB 2.5" laptop drives are the three options from Seagate that start at $230 (with a 13% saving)?

And you claim Apple are the ones wanting a premium!

(For comparison, a 1TB 5400 rpm drive is around $85-100)

There's a reason Apple went with the 5400 rpm 2.5" drive - it costs half as much on a machine they're targeting at the mid-range market. The performance delta between the two drives is minimal compared to what you get if you go for the Fusion drive.

So, they either take $100 hit on the profit per 21" iMac (realistically, it would be less since we'll assume a healthy volume discount for Apple) or they put the price up by $100 per iMac on a machine that is already more expensive than its competitors.

If you want the performance in that configuration you simply go for the Fusion drive - or you pay exactly what the Fusion upgrade costs ($250) and get one of those ludicrous 7200 rpm 1TB drives from Newegg and install it yourself.
 
AidenShaw said:
The early descriptions of Apple's implementation describe it as an OS-directed file-level placement technique. Where is it describes as a block-level optimization?
Click to expand...

Get your facts straight and read the articles published.......

"Fusion Drive is Apple's proprietary OS-level technology for block-level data tiering. It moves merges physical drives in a single logical volume and silently moves ..."
 
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joe-h2o said:
There's a reason Apple went with the 5400 rpm 2.5" drive - it costs half as much on a machine they're targeting at the mid-range market.
Click to expand...

Wrong.... Cost had nothing to do with it, the only reason was space in the 21" enclosure......
 
little.pm said:
1 * 1 / 100 = 1 / 100

2 * 1 / 100 = 1 / 50

the more drives you add the higher the risk that one will fail. (So, you add in even more and more drives to account for this ... Striped Mirrors, Striped Raids, Striped Raids of Mirrors ....)

🙂
Click to expand...

Two drives, four modes:

1% failure rate.

Both drives work: 0.99^2
One drive works: 2*0.01*0.99 (this mode can happen twice, hence the 2*)
Neither drive works: 0.01^2

Added together = 1

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joe-h2o said:
There's a reason Apple went with the 5400 rpm 2.5" drive - it costs half as much on a machine they're targeting at the mid-range market. The performance delta between the two drives is minimal compared to what you get if you go for the Fusion drive.
Click to expand...

The drive is sitting above the power supply with the one and only blower servicing the CPU/video heat sink and part of the power supply.

No fan on drive = heat issues. The 5400 laptop drive is the ony one that can survive in the heat. It also costs less.
 
Lancer said:
Dumb question but how, and will my external 2Tb now have more space?
Click to expand...

Apple started reporting HD size using decimal instead of binary with Snow Leopard. Binary reports a 1Tb drive as 931GB. Decimal reports the drive at about 997 GB. So starting with Snow Leopard you have more reported space to use. 🙂
 
MacDav said:
Apple started reporting HD size using decimal instead of binary with Snow Leopard. Binary reports a 1Tb drive as 931GB. Decimal reports the drive at about 997 GB. So starting with Snow Leopard you have more reported space to use. 🙂
Click to expand...
Thanks for clearing that up, I checked online but couldn't find much.

So it obviously would be any bigger in actual size, apart from the 128Gb SSD added to the 1Tb HDD.
 
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