SSD running SATA2 speed on my Mac Pro

LEOMODE said:

Hi I have 2010 June Mac Pro.

But since it's bottlenecked at SATA 2, my SSD is not getting the full power.

Since I'm not really good at modification, I was just wondering if I can change all my SATA2 cables to SATA3 so my SSD can get SATA 3 speed.

Or do I need an additional PCI slot card for SATA3 interface?

How can I upgrade from SATA2 to SATA3 in the convinient way possible?

Thanks for reading.

Click to expand...

Yours has : 4 - 3.0 Gbps Serial ATA (SATA) controllers
So, changing Cables won't work.

You need something similar to this, but this one says it does not support SSD, this was just a quick search though.

http://www.amazon.com/Crest-Port-SATA-PCI-Express-SY-PEX40039/dp/B005B0A6ZS

Edit: Strange they say it's SSD incompatible, SATA = SATA

Edit Again:

http://eshop.macsales.com/item/Newer%20Technology/MXPCIE6G2S2/

It is my....

understanding what the onboard controller in your machine is a SATA II. So, changing the cables will no work, IMHO. A wide selection of eSATA cards can be viewed here:

http://eshop.macsales.com/Search/Se...e=5000&N=6944&Ntt=Hard+Drive+Controller+Cards

Hope that helps

LEOMODE said:

Or do I need an additional PCI slot card for SATA3 interface?

Click to expand...

Yes.

...if I can change all my SATA2 cables to SATA3 so my SSD can get SATA 3 speed.

Click to expand...

No.

Look at this as well:
http://www.apricorn.com/vel-solox2.html

LEOMODE said:

Thanks, so if I put that SATA3 interface card next to my VGA slot, it would work fine correct..? I believe I have extra PCI slot available. (VGA using PCI 2.0x16, and other one is empty).

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Thanks.

For anyone who had plugged in SATA3 PCI card, is it just plug & play and done? Speed changed when I turn on my OS? (Windows 7 or Mac OSX)

Or do I have to install all the operating systems again since SATA interface has been changed? Sorry that I'm not really pro at these

Click to expand...

Look at the second link in my original post, I updated that one, there are windows drivers included so in windows it's not plug and play, but installing drivers is easy.

Edit: Took a closer look it's eSATA, not SATA.
(Are there SATA to eSATA Cables?)

I am currently using two Apricorn x2 adapters, with SSDs on them. It's pretty fast. I paid $99 each. I will probably not have use for one of them, so PM me if you want to buy it. The apricorn adapter is about 1 week old and I don't use my Mac Pro every day.

phoenixsan said:

understanding what the onboard controller in your machine is a SATA II. So, changing the cables will no work, IMHO. A wide selection of eSATA cards can be viewed here:

http://eshop.macsales.com/Search/Se...e=5000&N=6944&Ntt=Hard+Drive+Controller+Cards

Hope that helps

Click to expand...

This doesn't change the speed of the on-board sata-ii bus does it? What I'm trying to ask is "the drives in my 4 bays don't benefit from this card do they?"

ssls6 said:

This doesn't change the speed of the on-board sata-ii bus does it? What I'm trying to ask is "the drives in my 4 bays don't benefit from this card do they?"

Click to expand...

It won't affect them in any way. They're physically connected to another SATA controller. It would be rather impossible to take advantage of SATA-III in the 4 HD bays due to the way Apple designed them. One way would be to use a 5.25" -> 3.5"/2.5" adapter and put the drive in one of the optical drive bays and pull a SATA cable from there to the SATA-III controller in the PCIe slot.

It's really not worth the hassle or expense to upgrade to SATA3 for an OS/Apps drive. It may make sense for large media file operations.

I recently moved my Apps/OS SSD (Crucial M4) from the SATA2 backplane to a SATA3 Solo X2 card and it made zero difference in real life. It benchmarks fantastic now... but there really is absolutely zero noticeable difference in day-to-day usage.

Think about it... SATA2 tops out at around 275MB/s. SATA3 doubles that. But what else in your system, can possibly write to your SSD at 275MB/s or more such that the SATA2 bus is actually the bottleneck?! Likely only another SSD, or a file duplicate/copy. Both of those operations are extremely rare, and may cost you a fraction of a second here and there... something you likely won't even notice. On the read side... most desktop I/O reads are small random reads of 4KB block sizes... where all SSD's top out at around 20-25MB/s... an order of magnitude lower than your SATA2 bus speed. Similarly, it won't affect your boot time that much either since that's predominantly a function of the memory check and is otherwise somewhat CPU constrained and affected by device initialization, DHCP, and other things.

So while it may bring added peace to your life, knowing your SSD is connected to a SATA3 interface, it won't matter one bit to your real-life experience.

You can also just install your SSD on a Sonnet Tempo and keep the space for another hard drive available.

Think about it... SATA2 tops out at around 275MB/s. SATA3 doubles that. But what else in your system, can possibly write to your SSD at 275MB/s or more such that the SATA2 bus is actually the bottleneck?! Likely only another SSD, or a file duplicate/copy.

Click to expand...

RAM and L2/L3 cache.

Giuly said:

RAM and L2/L3 cache.

Click to expand...

Yes... if working with large media files. In that case, SATA3 and RAID0 (best in combination) make a difference, but for an average OS/Apps drive, the difference in SATA2 vs SATA3 is unnoticeable in every day use and simply not worth it.

LEOMODE said:

Hi I have 2010 June Mac Pro.

But since it's bottlenecked at SATA 2, my SSD is not getting the full power.

Since I'm not really good at modification, I was just wondering if I can change all my SATA2 cables to SATA3 so my SSD can get SATA 3 speed.

Or do I need an additional PCI slot card for SATA3 interface?

How can I upgrade from SATA2 to SATA3 in the convinient way possible?

Thanks for reading.

Click to expand...

There are a bunch of options like you're seeing being listed but... Any of them over about $50 are a waste of money IMO.

Why?

I'm so glad you asked.


See, aren't you glad you asked too?

.

VirtualRain said:

Yes... if working with large media files. In that case, SATA3 and RAID0 (best in combination) make a difference, but for an average OS/Apps drive, the difference in SATA2 vs SATA3 is unnoticeable in every day use and simply not worth it.

Click to expand...

When you launch an app, it gets loaded into the RAM.

Giuly said:

When you launch an app, it gets loaded into the RAM.

Click to expand...

Have you moved your OS/App drive from SATA2 to SATA3? I've also done this and I agree with the assertion that it makes no noticeable difference in actual usage.

Can't say I notice it. Except for phat benchmark numbers. Real world, no. As stated by others it matters more for end-to-end solutions. Like SSD to RAID AND the need to get over 270MB/s+ in workflow. Otherwise just driver based grief on the cheap and too much $ for too little benefit on the high end cards that can actually replace the Mac Pro backplane.

To understand why SATA3 is largely unnecessary for an OS/Apps drive, you really need to understand storage I/O access patterns for this kind of workload. Almost every researcher and benchmark utility on the planet characterizes an OS or workstation load as 80% Read, and 80% Random with an average 8K transfer size (see the chart below for a comparison). StorageReview.com uses exactly this storage pattern in their Workstation benchmark.

Of course, there's a lot more focus on this kind of research for server workloads, but there are still enough data points around that all suggest that your OS workload is primarily small random reads.

The only kinds of workloads that will push sequential workloads are sustained copies and large media files... but even those are usually not big enough, and therefore don't take long enough (at 275MB/s) to read or write for you to notice. Furthermore, a lot of I/O is actually CPU bound. Large files aren't just loaded directly into RAM... they need to be processed/rendered by the CPU.

Now with that knowledge in hand, if you look at any SSD benchmarks, you'll see that SSD's, while a couple orders of magnitude better than old HDDs are still only able to achieve around 20-30MB/s on random small block I/O.

So as I said before, a SATA3 interface will make your benchmarks look good, but it won't make even the slightest difference in every day use on an OS/Apps drive.

Now if you're moving large TIFF files or HD video files around, yes, SATA3 and RAID0 are your friend, but for the OP... it's probably a total waste of effort and money to migrate his SSD to a SATA3 interface. And I can tell you from first hand experience... it makes ZERO difference. (But I do store my photo libraries on a RAID0 Array of SSDs on a SATA3 RAID card).

I really can't tell any difference with my 2012 and a 512SSD compared to my 2012 MacBook Pro with an 512SSD (both OEM drives). And that is SATA2 vs SATA3. I do see the pinwheel during boot for about one turn on the Mac Pro and I don't see it at all on the MacBook Pro, but that's about it. Using it - I can't tell.

LEOMODE said:

Thanks a lot and also other people who have noted that it does not make any difference in real life usage!

I guess I wanted some kind of a difference (like HDD vs SSD in real life usage) and I guess if SATA2 and 3 doesn't really feel that much different in normal usage (such as loading apps, running games), then I guess I'll just settle down with this.

I thought that since the speed was twice as fast, I thought it would make a world of difference going from HDD to SSD cuz it did for me a lot. (Now I can never go back to HDD). Anyone agree?

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Just out of curiosity, is the upgrade from USB2.0 to USB3.0 on the same feel with upgrading from SATA2 to SATA3 then? Or is USB2.0 to USB3.0 more like HDD to SSD?

Click to expand...

The problem with assessing storage speed is that vendors always publish sustained transfer rates (STR) or in other words, max sequential read/write speed. A typical laptop HD has a max STR of about 100MB/s. A modern SSD can do about 500MB/s. And you'd think, wow, that's 5x faster. And you're right, but that's not even close to the reason SSD's seem so fast.

The fact is, as I stated in my long essay a few posts back, is that most desktop usage is random small block I/O. On this kind of storage profile, access time becomes king... not STR. Now a typical laptop HD has an access time of around 5-8ms with extreme values of perhaps 100ms or more if the head happens to be on the wrong part of the disk. On the other hand, SSD's have access times around 0.04 or 0.05ms. Thats 100X better performance than an old-fashioned HD.

So the reason SSD's are game changers, is not the fact that they have 5x the sustained sequential transfer rate of an old HD. It's the fact that they have 100x less latency for random I/O. (Although as I said above, that 5x STR improvement coupled with RAID0 can become a game change for managing large media files).

Now, will USB3 make a difference vs USB2? It really depends what you connect to it, and how you use it. Connect an SSD to a USB3 port and yeah, it's going to fly compared to a HD on a USB2 port. But just moving the same HD from USB2 to USB3 is only going to have an incremental improvement (if any) depending on what kind of I/O you're doing through that connection.

VirtualRain said:

Now, will USB3 make a difference vs USB2? It really depends what you connect to it, and how you use it. Connect an SSD to a USB3 port and yeah, it's going to fly compared to a HD on a USB2 port. But just moving the same HD from USB2 to USB3 is only going to have an incremental improvement (if any) depending on what kind of I/O you're doing through that connection.

Click to expand...

Yup!

The same thing as you are explaining about SATA III vs SATA II for system partitions applies here too. If you put the SSD on USB2 and install OS X on it the boot times and general performance will be fairly close to the same as if the same SSD were installed internally on a SATA III (PCIe card). And for the same reasons as you give concerning the SATA II vs SATA III differences.


Should be very very close to the same. You might take a 10% hit if your system was an SSD. Otherwise I doubt your stopwatch is accurate enough to record the differences.

Almost all of the OS loads at about 20MB/s to 30MB/s from an SSD by my calculations. USB2.0 delivers 40MB/s reads. So there ya have it.... It'll be almost the same (for booting and small files).






I tried that as an experiment at first and then just kept it like that for about 3 months. Too lazy you open the case and speeds were the same anyway.

Well USB has protocol overhead where SATA is disk native, so you will get better performance with less issues using SATA for drives you are booting from or moving a lot of data to/from.

As stated in several posts, and I can attest to via extensive lab tests, point to point SATA III is a waste of money with your current SSD as there is no speed or performance advantage over SATA II unless you add port multiplier or RAID controllers PCI cards.

RAM disks are different, and there are $$$ drives that like SATA III or SAS.

Just because the interface pipe (SATA or USB) gets bigger, it doesn't mean SSDs can handle it. If you have a small transactions (unlikely unless you are running a commercial server in a bank).

Drives are always being improved, however. Next year it may be a different story... but then the OP would be looking at a different drive.

They both have a protocol overhead. For SATA it's 2 bits out of every ten.

But no matter... The graphs i posted are after all is considered and done. That's actual user data.