[Rev2Liv]

Hello y'all,

I'm planning on upgrading the stock 256GB SSD in my 2011 27" iMac to a modern 256GB 6G SSD and i'd like to know what to expect performance wise?

The stock Apple drive OEM Toshiba 256GB Transfers at only SATA 3G speeds. The upgrade will features SATA 6G speeds.

The main drives i'm contemplating are the Samsung 840 and 840 Pro. Any other suggestions in the $150-$240 range for a 256GB SSD?

What performance improvements in terms of real world usability can I expect? Will it boot faster? Feel snappier? The stock Apple 256GB is atrociously slow benchmark wise but im wondering if the performance improvements justify the cost.

Thanks!

[mduell]

No difference outside of synthetic benchmarks. You won't notice it at all.

Amdahl's law contributes a good bit to this. The advantage of even a lousy SSD over a HDD is where most of the gains are.

[CharlesS]

Performance might actually get worse, out of the box, since the SSD that came with your Mac is probably TRIM-enabled, whereas Apple still disables TRIM support for third party SSDs unless you run TRIM Enabler or something.

[Rev2Liv]

Originally Posted by mduell 

No difference outside of synthetic benchmarks. You won't notice it at all.

Amdahl's law contributes a good bit to this. The advantage of even a lousy SSD over a HDD is where most of the gains are.

Synthetic benchmarks show a HUGE gap in performance. The SATA 3GB is easily saturated and is a bottleneck.

I'm looking for real world experience for those who have upgraded a stock Apple SSD running at SATA 3GB and then swtiched to a SATA 6GB.

[P]

I did something like that, although not from Apple stock - original Sandforce drive (3 Gbps) to Samsung 830 (6 Gbps) . Absolutely no difference. Maximum transfer bandwidth is irrelevant at speeds this high.

(I didn't do it for the performance, I did it because I wanted a bigger drive, and I made use of the Sandforce drive in another build).

[mduell]

Originally Posted by Rev2Liv 

Synthetic benchmarks show a HUGE gap in performance. The SATA 3GB is easily saturated and is a bottleneck.

That's both true and irrelevant. You don't spend that much time transferring >300MBps. Nor do you spend it doing 2000+ IOPS. You don't have anything to feed or consume it that fast.

[FireWire]

So, even if my 2007 iMac is limited to 3 GB/s, I would gain a lot by switching to a SSD?

[mduell]

Yes, absolutely. The improvement in seek time and random read/write throughput is fantastic.

[shabbasuraj]

Originally Posted by FireWire 

So, even if my 2007 iMac is limited to 3 GB/s, I would gain a lot by switching to a SSD?

The difference would be like night and day.

Switching to an ssd regardless, of 3 or 6GB/s would be noticeable.

[Rev2Liv]

Will the iMac and Mac OS X act any snappier with the newest Samsung 840 Pro 256GB SSD?

[OreoCookie]

Yes, definitely.

[Rev2Liv]

I just bought and installed a Sony-Optiarc BD-5850H Blu-Ray burner for the total su of $79! Great bargain! Works too! Now all I need is to buy that Mac blu-ray software.