# iMac SSD Pros & Cons - Internal vs External



## MacDaddy68 (Dec 1, 2009)

Before buying a new iMac, I thought it would be interesting to discuss the merits of an SSD. I know many of us here "desire" the performance boost that an SSD will give to our OS and Apps. But what if you want to maximize dollars, utility and a future upgrade path? Funny enough, there are a lot of choices to think about.

*Internal SSD:*
Cons
- more expensive (due to 256GB minimum size from Apple)
- slower (compared to aftermarket)
- hard to replace or add later (2011 versions)
- adds to heat build up (however minor that may prove)
Pros
- easy BTO 
- full Applecare coverage
- large sizes (if you need it)

*External SSD:*
Cons
- availability unknown (probably within a few months though)
- cost unknown (could be high initially)
- takes up desktop space (may not be an issue if you have room)
- still have mechanical HD noise (I think)
- unsure if it can be used as a boot drive (rumors say it will be) 
Pros
- "probably" cheaper (especially if smaller size is chosen)
- adds utility (can swap super easy)
- won't add heat to iMac internals 
- adds an array of SSD choice (always nice)
- faster than internal on 2 fronts (TB vs SATA II connection + the drive itself)

My thought was: buy a new iMac now with a std HD then later add a bunch of RAM and a small external Thunderbolt SSD (for the OS and Apps). This not only saves money, but gives a nice performance boost (any new computer should), a tidy upgrade path and some extra utility as time goes by.


----------



## Dr T (May 16, 2009)

*Solid State Drive*



MacDaddy68 said:


> Before buying a new iMac, I thought it would be interesting to discuss the merits of an SSD. I know many of us here "desire" the performance boost that an SSD will give to our OS and Apps.
> ....
> - easy BTO
> .....


Prior to discussing the merits of two alternative forms of Solid State Drive, maybe someone could clarify something much more basic:

What is the Solid State Drive used for? To store the Operating System and Applications? Or the user's data files? Why is there any advantage at all to this Solid State Drive being added on to the conventional internal hard drive?

I have looked through the Apple website for answers, and have not found them. 

I have figured out the other abbrevs, but what is BTO in this context?


----------



## Paddy (Jul 13, 2004)

BTO=Built To Order (ie: not the standard issue iMac, but one you've modified in the ordering process)

Generally, faster access time is what gives an SSD the edge. See this set of tests for lots of info and insight:

Review/Performance tests of 32GB SSD vs 10,000 RPM (VelociRaptor and Raptor) hard disks

More info from people who've installed SSDs as boot drives here: YouTube - ‪SSD vs SATA‬‏

and here: How to speed up your mac with a Solid State SSD Drive

As you can see, they're typically not faster at writing, so using them as boot drives rather than data disks makes sense. Although I've also seen some people recommending their use for Photoshop scratch disks...(where they're both written to and read - presumably the reading back out speed makes a difference to the overall speed of operations) At any rate, there seems to be some debate about the benefits, especially when compared to either a RAID or RAMdisk for this purpose. You'd need LOTS of RAM for the latter, needless to say.


----------



## MacDaddy68 (Dec 1, 2009)

Yes, there are advantages to SSD's. You'd primarily want to use one for only your OS and Applications, as it's still too expensive as a storage drive. The benefits?

- Faster boot time (mind you, not a big deal for desktops)
- Faster for opening applications
- Faster for accessing documents

Overall, most people suggest SSD's make your machine much more "snappy". Typical 7200rpm hard drives become the bottleneck each time they are accessed (as they are the slowest part of the data chain). Once you supplant this with an SSD, things get much much quicker within most applications. Plus, being solid state - they don't have any moving parts to wear out.


----------



## screature (May 14, 2007)

MacDaddy68 said:


> Before buying a new iMac, I thought it would be interesting to discuss the merits of an SSD. I know many of us here "desire" the performance boost that an SSD will give to our OS and Apps. But what if you want to maximize dollars, utility and a future upgrade path? Funny enough, there are a lot of choices to think about.
> 
> *Internal SSD:*
> Cons
> ...


An external SSD will make no more noise than an internal SSD and you will be throttled to the speed limitation to the FW800 bus negating all speed advantages of the SSD. There will be an actual LOSS in speed relative to a mechanical HD. There is very negligible heat produced by an SSD. Therefore on an iMac without Thunderbolt there is *zero* advantage to an external SSD... Zero.

I think you need to do some more research.


----------



## Paddy (Jul 13, 2004)

screature said:


> An external SSD will make no more noise than an internal SSD and you will be throttled to the speed limitation to the FW800 bus negating all speed advantages of the SSD. Therefore on an iMac without Thunderbolt there is zero advantage to an external SSD. Zero.


Don't think he was considering going the FW route, Screature. 



> My thought was: buy a new iMac now with a std HD then later add a bunch of RAM and *a small external Thunderbolt SSD* (for the OS and Apps). This not only saves money, but gives a nice performance boost (any new computer should), a tidy upgrade path and some extra utility as time goes by.


----------



## screature (May 14, 2007)

Paddy said:


> BTO=Built To Order (ie: not the standard issue iMac, but one you've modified in the ordering process)
> 
> Generally, faster access time is what gives an SSD the edge. See this set of tests for lots of info and insight:
> 
> ...


SSDs are *much* faster at writing depending on the block size and for a boot drive the block size is generally small (so long as you keep your data on a separate drive, which I *always* do and is *always* recommended for top performance). SSD's are the fastest boot drives available. Period. For use as data drives writing large files not so much.


----------



## screature (May 14, 2007)

Paddy said:


> Don't think he was considering going the FW route, Screature.


Thanks Paddy I missed that part but until there are products available to allow SSD connection via Thunderbolt... who cares.


----------



## MacDaddy68 (Dec 1, 2009)

Wasn't suggesting an External SSD would make noise... I probably messed that point up (comparing it to a machine with a 7200 drive - as I mention in my last paragraph).

Also, I was referring to the new Thunderbolt new equipped iMac's not the last gen with FW800.


----------



## screature (May 14, 2007)

MacDaddy68 said:


> Wasn't suggesting an External SSD would make noise... I probably messed that point up (comparing it to a machine with a 7200 drive - as I mention in my last paragraph).
> 
> Also, I was referring to the new Thunderbolt new equipped iMac's not the last gen with FW800.


But what product is available to allow you to do that now at a reasonable price compared to the BTO option?


----------



## MacDaddy68 (Dec 1, 2009)

> Thanks Paddy I missed that part but until there are products available to allow SSD connection via Thunderbolt... who cares.


Umm... I care. And I bet there's probably others on this very board who are also ready to pull the trigger, wondering the same thing. Besides, what harm is there to speculation?


----------



## MacDaddy68 (Dec 1, 2009)

> But what product is available to allow you to do that now at a reasonable price compared to the BTO option?


Again, there isn't. But I did list that there were definitely some unknowns in my original post.


----------



## Paddy (Jul 13, 2004)

screature said:


> SSDs are *much* faster at writing depending on the block size and for a boot drive the block size is generally small (so long as you keep your data on a separate drive, which I *always* do and is *always* recommended for top performance). SSD's are the fastest boot drives available. Period. For use as data drives writing large files not so much.


Um, if you look at the tests in the first link, the write times for the Velociraptor were much better for small blocks, and not as good for the larger blocks, compared to the SSD.

Here are the comments re: the Quickbench "small write" tests:



> The SSD fares poorly in this test, because of its achilles heel "small writes". Apparently there are not enough (or not distributed enough) writes to make up for it with its access time advantage.
> This achilles heel of the SSD is due to "erase blocks": Wherease a disk can write small blocks of typically 512 bytes in size, the blocks are much larger for SSDs. First, the block has to be read into the cache, the data changed in the cache, and the full block written back to disk. So small writes have a lot of overhead.
> I don't know how large the erase blocks are for the MemoRight GT SSD, for other SSDs they can be as small as 16 KB or as large as 1 to 4 MB (reportedly). I'd venture a guess that the erase blocks are rather largish for the MemoRight GT, so it reaches good random writes scores only if the blocks are large enough./QUOTE]


----------



## screature (May 14, 2007)

MacDaddy68 said:


> Umm... I care. And I bet there's probably others on this very board who are also ready to pull the trigger, wondering the same thing. Besides, what harm is there to speculation?





MacDaddy68 said:


> Again, there isn't. But I did list that there were definitely some unknowns in my original post.


Sorry MacDaddy68 for my terse attitude... long day, my bad.

Here's the thing... if you want to buy *now *and want the full performance of an SSD *now* on an iMac there is only one option... BTO there are currently really no other alternatives *now*.

The reason I keep emphasizing *now* is that if you don't *need* it now don't buy it now... IMO that is the first rule of buying when it comes to technology... make do as long as you can, things will almost always be better and cheaper (or at least comparably priced for better performance) in the future.


----------



## screature (May 14, 2007)

Paddy said:


> Um, if you look at the tests in the first link, the write times for the Velociraptor were much better for small blocks, and not as good for the larger blocks, compared to the SSD.
> 
> Here are the comments re: the Quickbench "small write" tests:
> 
> ...


Did you happen to notice the year of the writing of that article Paddy... *2008*.  You need to get with the program. 

This is a fast moving area of technology and 2008 is ancient history.


----------



## Paddy (Jul 13, 2004)

Sigh...there seems to be a dearth of RECENT benchmarks showing an SSD vs an SATA drive (or SATA RAID setup) - most of the benchmarks just show the new SSDs compared to each other. 

However, here's one from this year, though it is average write/average read, not different sized blocks. Still quite interesting how it comes out though:

Disk Benchmarks: SSD vs. "Raptor" vs. RAID - Random Musings of Jeremy Jameson - Site Home - MSDN Blogs

Of course, you can't put a RAID IN an iMac.


----------



## Andrew Pratt (Feb 16, 2007)

> Of course, you can't put a RAID IN an iMac


Actually you can. Install a second drive in the optical bay and do a software RAID...not as good as hardware but technically still RAID 

Having lived with a few SSD's there's no going back once you've had them...they are amazing. Until we see the prices on thunder bolt cases it is pure speculation that it will be cheaper. I'd bet that an external plus high end SSD would be faster then an BTO Apple SSD but I'm not so sure it would be cheaper.

There is a 3rd option...buy the regular harddrive model and then install an SSD yourself (or have OWC do it for you)


----------



## smashedbanana (Sep 23, 2006)

I'm not sure why people are comparing SSD to the raptor/velocipator. 

Can you order the raptor BTO with the imac? I don't think so.

Personally I'd wait for SSD to come down in price of thunderbolt options.

I had a 50GB Vertex2 SSD (285mb/275mb) in my macbook for awhile. It rocked but it was too small and I went to a 500gb s-ata. I also had to RMA it once 

Big SSDs are too expensive, especially since the Tsunami (prices on them went up after it)..


----------



## screature (May 14, 2007)

Paddy said:


> Sigh...there seems to be a dearth of RECENT benchmarks showing an SSD vs an SATA drive (or SATA RAID setup) - most of the benchmarks just show the new SSDs compared to each other.
> 
> However, here's one from this year, though it is average write/average read, not different sized blocks. Still quite interesting how it comes out though:
> 
> ...


Sigh... This review does not compare apples to apples stripe a pair of SSDs RAID 0 and see how it would blow the doors off of any HDs. 

Again, as I have said, for a boot drive where you are not storing data just running the OS and programs (which this fellow was not doing) an SSD, especially one like the OCZ Vertex or the OWC Mercury Extreme Pro, is simply a much faster boot drive. As I also said, if you are writing large block files as you would be with say video or even large Photoshop files an SSD is not necessarily the way to go.

I know this for a fact as I replaced a RAID 0 WD Raptor (2 x 74GB 10,000RPM) array boot disk (running only the OS and programs) with a 120GB OWC Mercury Extreme Pro and there is quite simply no comparison, it was the single best performance upgrade I have ever made and that includes upgrading my CPU from a quad 2.66GHz to a quad 3.0GHz and adding 11GB of RAM.


----------



## screature (May 14, 2007)

smashedbanana said:


> I'm not sure why people are comparing SSD to the raptor/velocipator.
> 
> Can you order the raptor BTO with the imac? I don't think so.
> 
> ...


Not on the OWC Mercury Extreme Pro, they are made in the US. 

Expensive is relative. For top boot disk performance where the SSD just runs the OS and programs you don't need a very large SSD. I have a 120GB OWC Mercury Extreme Pro and fits OSX and all my programs on it quite comfortably. It was $240, sure on a $/GB basis that is expensive these days but it put new life into my old Mac Pro 1.1 and that is a heck of lot cheaper than upgrading to a new Mac Pro.


----------



## Andrew Pratt (Feb 16, 2007)

> but it put new life into my old Mac Pro 1.1 and that is a heck of lot cheaper than upgrading to a new Mac Pro.


I did the same with my old MacBook Pro...it turned that machine into a rocket ship and I'll be upgrading my new MBP as well.


----------



## Guest (Jun 11, 2011)

I did a pair of 60G SSD's in a RAID0 (striped) internally in my Mac Pro. Totally ridiculous throughput and amazingly fast bootups and applications launches. I also back it up very regularly


----------



## CanadaRAM (Jul 24, 2005)

screature said:


> Not on the OWC Mercury Extreme Pro, they are made in the US.


Depends how you define "made". They -may- be assembled in the US (or they may just be labelled in the US) but the NAND Flash chips, controllers, circuit board and connectors almost certainly are all from the Far East. Which of these components would be affected by a disruption in the Japanese supply chain is up for debate.


----------



## screature (May 14, 2007)

CanadaRAM said:


> Depends how you define "made". They -may- be assembled in the US (or they may just be labelled in the US) but the NAND Flash chips, controllers, circuit board and connectors almost certainly are all from the Far East. *Which of these components would be affected by a disruption in the Japanese supply chain is up for debate*.


Agreed. There actually could be some supply issues on some of the parts:



> Designed and built in the U.S. from domestic and imported parts


I would think many of these components are (may be) made in China as well I believe. In a photo of the OWC Mercury Extreme Pro disassembled St StorageReview.com the SandForce chip is stamped Taiwan so at least on that front there would be no supply issues. 

Regardless, the prices have not risen on the OWC Mercury Extreme Pro SSDs since the earthquake and tsunami in Japan.


----------

