Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

scott911

macrumors 6502a
Original poster
Aug 24, 2009
758
456
I just bought a new 27" retina imac with the 7200 RPM drive only, and am a bit underwhelmed.
I already get the sense that it's slower that the seven year old PC it's replacing - that one has a cheap SATA SSD drive I installed a couple years ago. I certainly wasn't expecting this and am worried about the imac's ability to keep up in future.

Anyway - While my return period is still open, I've been looking at what to do.

1 - taking the imac apart to the extent needed to put in a blade SSD is beyond what I want to risk, so I think that eliminates that future upgrade option for me. That would be the best option - especially in a year or two when those blase SSD's are bigger and cheaper. But I'm chicken...

2 - I could put in a nice big SATA SSD to replace the 1 TB spinner in there now. After reading ifixit, I'm sure I could do that... But I'm annoyed that the current SATA SSD are so much slower than the hard-to-get-to Blade.

3 - And here's the question - if a wait a year or two, will future easily-replaceable SATA SSD be as fast as the blades of today? If they could be (& not limited by their sata interface) that'd a nice option to look forward to, and would make me more comfortable to keep this imac knowing I could speed it up in future...​

thanks in advance for you kind advice!
 
Last edited:

Pakaku

macrumors 68040
Aug 29, 2009
3,147
4,463
Do you need the speed badly enough? SSDs are fast enough right now. It doesn't seem like you need blade-speeds, otherwise why would you wait two years for the opportunity?
 
  • Like
Reactions: scott911

Fishrrman

macrumors Penryn
Feb 20, 2009
28,402
12,526
If by "SATA" you mean the -current- implementation of SATA, my guess would be "no".

SATA (as it is now) will eventually go the say of IDE (PATA) before it.

PCI-e (and faster) is the way of the future...
 

redheeler

macrumors G3
Oct 17, 2014
8,421
8,843
Colorado, USA
No, as far as I know the SATA interface in the iMacs is limited to 600 MB/s which is half as fast as the current SSD blades. Your best bet of getting something similarly fast in the future would be using Thunderbolt. Right now I recommend you return your iMac and get one that has an SSD, Apple should have stopped selling iMacs with only mechanical drives in 2013.
 
Last edited:
  • Like
Reactions: scott911

h9826790

macrumors P6
Apr 3, 2014
16,614
8,546
Hong Kong
If you are talking about the max sequential read / write speed, which usually the the benchmark will show you. The answer is NO.

If you are talking about the high IOPS which make you "feel" that your machine is much more responsive. The answer is may be.

Anyway, if I were you, I will simply replace the HDD by a 2T 850 Evo (or may be 1T if that's enough for you). That should be more then enough to make you feel the speed.

For most users, what they really need is the high IOPS (important to small files read / write. .e.g. OS operation, managing photos, etc), but not high sequential speed (good for large file copy / 4K video editing, etc).

I doubt if a SATA SSD can ACTUALLY as fast as the PCIe SSD. However, the scale in real world is something like this.

Boot time
HDD: +60s
SATA SSD: 17s
PCIe SSD: 17s

(Overclock.net review confirms that the boot time won't be affected by the SSD's connection interface)
900x900px-LL-1fb52e74_Screenshot_1.png


Open a large app
HDD: +10s
SATA SSD: 1.5s
PCIe SSD 1.2s

(Tom's Hardware review confirms that there is virtually no difference on boot + loading apps between SATA 2 and SATA 3 connection)
realworld_MultiAppStart.png


As you can see. The boot time affected only by small files read /write can't even saturate the SATA 3 bandwidth, therefore, PCIe speed is doing nothing in here.

(The 4k random read / write speed not even close to the SATA 2 limit 250MB/s. And this chart also shows SSD is 30 times faster than spinner in small files read / write. This is actually what a normal user need.)
AS-SSD_Sequential_Random_4KB_QD_1.png


For large apps opening. The PCIe SSD may be tiny bit faster than SATA SSD, technically, it's still faster. However, in human being scale, the difference is virtually nothing.

If I can get a large PCIe SSD with just little bit extra cost. I will definitely go for PCIe SSD. However, if the SATA SSD is significantly cheaper. I will go for SATA SSD at this moment. Which gives me much better cost to performance ratio. And virtually the same "feeling" most of the time.

It is a little bit like the fusion drive. As long as it match your usage pattern / fit your need. You can have a system that virtually has same speed, but more storage, and cheaper.

It's nothing wrong to go for faster SSD, however, for most real world application, the bottleneck simply not at the connection interface, but the drive's latency. Since SSD introduced, the significant latency is not there any more. Further improve the connection speed won't help anything because the bottleneck is not at there from the very beginning.

There is another post about more RAM not necessary can do anything to the system. This is the same case. More RAM always good, but the user may never able to utilise it. Go for PCIe SSD of course is good, but again, for some users, they may never really utilise that speed. And PCIe SSD still cost quite a bit more then SATA SSD at this moment. For most normal users, the expected performance improvement simply not there even though they pay for the extra premium.
 
Last edited:
  • Like
Reactions: scott911

scott911

macrumors 6502a
Original poster
Aug 24, 2009
758
456
Thanks for the replies all - to answer a couple questions - I went with the spinner because best buy was offering a $300 promo on just that model - and otherwise, I couldn't afford the 27" model...

I'm relatively satisfied with the speed now, I'm just worried that after a few OS updates down the road, that my upgrade option will be limited.

From my experience on the PC side, I know that simply replacing the HDD with a nice 'traditional' SSD like h982679 suggest will certainly help - or a thunderbolt external like redheeler suggests

So - I feel I have a good options down the road - not the mention the ability to thankfully still have accessible memory slots...
 

throAU

macrumors G3
Feb 13, 2012
8,893
7,054
Perth, Western Australia
SATA is dead. Doubt there will be a new SATA version, and the ports you have will be SATA3 (or older).

Do not expect there to me much future development in that standard. SSD don't need much of the overhead that SATA contains because SATA was meant to drive spinning drives and all the logic that entails. For the disks that need SATA (i.e., spinning rust) they aren't even fast enough to saturate SATA3, so...

On the other hand, even slow SSDs today are faster than the SATA3 bus - thats the limiting factor on most SATA drives, not the SSD speed itself, just the bus isn't fast enough.

Hence M.2, PCIe, etc.

So yeah, if you have SATA ports in a current machine, yes they are obsolete and today's SATA SSD performance is about the best you can expect out of them. The SATA3 bus can only handle 550-600 megabytes per second (i.e., SATA3 6 gigBIT per second bus). The PCIe and M.2 SSDs are hitting 1400-1500 MB/sec already today - or about 3x the max you'll ever see in SATA.
 
  • Like
Reactions: scott911

scott911

macrumors 6502a
Original poster
Aug 24, 2009
758
456
and maybe - when warranty is way over, and it's no longer shiny and new, I'll pull out the dremel and carve a little door into back of case so I pop an express blade SSD right onto back of the logic board. :)
 

throAU

macrumors G3
Feb 13, 2012
8,893
7,054
Perth, Western Australia
Your best bet would be to just hook up SSD via thunderbolt if/when there's a thunderbolt-> PCIe/M.2 SSD adapter (which there probably will be at some point, if not now). Thunderbolt is quick enough to run PCIe SSDs at much faster than SATA speed. Thunderbolt 2's 20 Gigabit = 3+ times faster than SATA3 ports.
 
  • Like
Reactions: scott911

le.bouch

macrumors regular
Aug 3, 2010
163
73
You say replacing the spinner with an SSD is within your skills but fitting a blade is not. I'd disagree. Having fitted blades to both a 21" and 27" iMac (both late 2012 models) I'd say by far the worse bit is removing and refitting the screen.
The 27" is much easier to work on (more space) and removing the logic board is no big deal, certainly if you've got the balls to remove the screen!
 
  • Like
Reactions: scott911

Fishrrman

macrumors Penryn
Feb 20, 2009
28,402
12,526
OP wrote:
"Thanks for the replies all - to answer a couple questions - I went with the spinner because best buy was offering a $300 promo on just that model - and otherwise, I couldn't afford the 27" model... "

If you'd like to see a BIG performance increase without spending a lot of money, just buy one of these and plug it into the USB port:
http://www.amazon.com/exec/obidos/ASIN/B00ZTRY532?tag=delt-20

You should get writes of about 430mbps and reads around 330mbps.

Compare that to what you're getting now (use the BlackMagic utility to check).

You can set up the external SSD to be your boot volume, with the OS, applications, and "stripped down" accounts.
By "stripped down", I mean that you store your LARGE libraries of stuff (music, photos, movies) on the internal HDD, leaving the boot SSD "lean and clean".

Do as I've outlined above, and you will TRANSFORM that iMac completely.
 
  • Like
Reactions: scott911

awer25

macrumors 65816
Apr 30, 2011
1,100
327
OP - just get a fast 2.5" SATA SSD if it's easier to install. I upgraded from a Samsung 850 SATA SSD to a Samsung 950 M.2 SSD, and honestly didn't feel much difference. Boot times, app startup times, etc were the same despite the 950 having up to 3.5x the read speed.
 

throAU

macrumors G3
Feb 13, 2012
8,893
7,054
Perth, Western Australia
Does depend what you're doing but yes even a USB 3 connected SSD is fast enough for most and way quicker than a hard drive.

But the OPs original concern was getting left behind with sata3 ports and native sata3 is quicker than usb3. Better than sata3 will require fitting a blade SSD or using thunderbolt.
 
  • Like
Reactions: scott911
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.