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Has anyone tried the OWC Accelsior S?

djjaes said:
I have dowloaded AJA, but the read speeds are not any better than what BM demonstrated....I have not yet switched the slot, but I plan on this this weekend.
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I plan on trying this weekend when I have the time to test the system. TBA
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I have tried the drive in all slots, and have similar low read speeds. I am returning the adapter. It is too late to return the SSD to Best Buy, so I will get another drive and another adapter at a later time.
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h9826790 said:
I never own / try this OWC adaptor, but recognise as external is normal. All hard drivers connected via PCIe slots are considered external on the cMP.

However, the "read only" is definitely something wrong. But since this your boot drive. You may try to boot into recovery partition, and then perform both partition and disk first aid. Hopefully it can fix the permission issue. HOWEVER, if the SSD was 100% OK when connected directly to the native SATA II port, before I try any fix. I will put that back to one of the SATA II port and Test again. Just in case it's the adaptor causing the issue.

If the SSD work flawlessly again in the SATA II port, then you better call OWC and ask for support / refund, etc. It's not the SSD / macOS fault. No point to fix the item that's not the root cause.
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Correction to my post:

Write speed at last check with AJA is 92 MB/SEC and read speed 513 MB/SEC...I think the write speed is very low. Regardless on slot, X4 X16, read/write are about the same. On SATA II slot, the read/write speeds are a bit different, with write at 90 to 100 MB/SEC and read at around 300ish MB/SEC.
 
djjaes said:
I have tried the drive in all slots, and have similar low read speeds. I am returning the adapter. It is too late to return the SSD to Best Buy, so I will get another drive and another adapter at a later time.
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Correction to my post:

Write speed at last check with AJA is 92 MB/SEC and read speed 513 MB/SEC...I think the write speed is very low. Regardless on slot, X4 X16, read/write are about the same. On SATA II slot, the read/write speeds are a bit different, with write at 90 to 100 MB/SEC and read at around 300ish MB/SEC.
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Sounds like you didn’t enable TRIM.
 
djjaes said:
I have enable TRIM now. Still the same results. I am now believing the SSD itself could be the issue.
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Just enabling TRIM won't do much by itself. You need to run the disk utility to actually TRIM free space and get a big pool of free space. (See http://hints.macworld.com/article.php?story=20120114214648388 - but ignore the OWC propaganda about "TRIM not needed".)

(Ideally, you'd wipe the disk with "Secure Erase", then restore your files. That almost instantly marks the entire disk as free.)

The reason is that enabling TRIM means that *in the future* the OS will tell the SSD when files are deleted - so that the SSD can mark the space as "not in use". (The SSD doesn't know about files, so the OS actually sends the SSD a list of the LBAs (logical block addresses) that have been freed.)

The disk utility will scan the disk, and send TRIM commands for blocks that the filesystem says are empty. Without this scan, the SSD can't recognize the current unused space in the filesystem.

The main advantage of the "Secure Erase" is that over-provisioned space will also be TRIM'd. Over-provisioning helps because it means that the SSD has space that the user can't see, and it uses that space for moving stuff around and garbage collection. A typical 256GB SSD probably has 256GiB of flash - or about 7% of the total space is hidden from the user and is available for housekeeping. Since it's hidden, Disk Utility can't TRIM it.

A good description of what is happening is at https://en.wikipedia.org/wiki/Write_amplification .
 
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I have 3 of these Accelsior S cards, one each in two 2009 MP, and a 2012 MP.
I use Samsung 850 EVO in two of them, and an 850 PRO in the other.

All three show over 500MB/s read and write in slot 2 or 3.
I have never tried them in the top slot.
 
Surrat said:
I have 3 of these Accelsior S cards, one each in two 2009 MP, and a 2012 MP.
I use Samsung 850 EVO in two of them, and an 850 PRO in the other.

All three show over 500MB/s read and write in slot 2 or 3.
I have never tried them in the top slot.
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I plan on getting an EVO in the near future since I believe my SanDisk is the kink in the chain.
 
I have since my original post gotten an EVO 860. The read speeds in the PCIe are as advertised. The OWC card was not at fault. The SanDisk SSD had low write speeds with high read speeds. I will simply use it as a backup or other drive, too late to return to Best Buy. Thanks for the help guys!
 
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How is Trim handled on a non-system disk?
I am looking to replace a hdd with a pci-e ssd (sonnet tempo + evo).
This drive is purely data.
Do you have to navigate to that drive in terminal to enable trim?
 
MarkC426 said:
How is Trim handled on a non-system disk?
I am looking to replace a hdd with a pci-e ssd (sonnet tempo + evo).
This drive is purely data.
Do you have to navigate to that drive in terminal to enable trim?
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It's system wide, either all on or all off regardless the SSD is for OS or data.
 
flowrider said:
Did you try to enable TRIM yourself? It is not self enabling except with an SSD identified as an Apple device.

I am running five Samsung SSDs. One SM 951 and four 840 devices. All have TRIM enabled. Two are mounted on the SATA bus. The other three are on PCIE cards. Attached are my write/read speed readings. The first is an 840 on the SATA Bus. The second is an 840 on a Velocity x2 PCIe card.

Note: You may have guessed from some of my previous posts, that I am no fan of OWC.

View attachment 732304 View attachment 732305

Lou
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I just installed the AJA utility and ran it on both of my ssd’s (both on sata, no trim enabled) and got identical results to yours :D
Maybe because I never really delete anything.
I have a sonnet tempo card and ssd on the way, so hopefully that should show double the speed.
 
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Got my Sonnet Tempo card......

SSD in SATA port

sata ssd.jpg


SSD in PCIe port

pcie ssd.jpg


Still not enabled Trim......:)
 
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I have the same results in my Mac Pro with an Accelsior PCI and a Samsung EVO SSD SATA III and a Neptune OWC in a drive bay SATA II, but TRIM is enabled. In the beginning I didn't enable TRIM and after a month the SSD speeds decreased significantly.
 
That is interesting.....I initially ran the AJA test on my system ssd (using the 1gb file) and got the ~260 results.
But re-ran it with the 16gb file, it started at 260, but about half way through the test dropped to about 150. (The faster result above is a blank ssd).
Maybe its time to enable trim.
 
MarkC426 said:
That is interesting.....I initially ran the AJA test on my system ssd (using the 1gb file) and got the ~260 results.
But re-ran it with the 16gb file, it started at 260, but about half way through the test dropped to about 150. (The faster result above is a blank ssd).
Maybe its time to enable trim.
Click to expand...

That's exactly what TRIM can deliver. Keep the high writing speed.
 
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One question:

Will this significantly improve speed with Lightroom catalogues for example?

Like when editing a photo and it's loading the entire 50MB raw file for 1:1 view or appliying masks/brushes and so on?

I understand the 2x performance boost when transferring big files is guaranteed, but in 50MB (or less files), will it actually make a big difference?

Or will more RAM actually be the best upgrade to do?
 
My Accelsior completely died. Fortunately, I had a clone to an SSD, which I was able to flip over to. I cannot seem to do anything to resurrect the Accelsior, nor is it really accessible in Disk Utility. If anyone has any ideas about how I might try to resurrect it, by all means, please let me know.

Thank you.
 
Did you try to boot in the recovery mode and erase with disk utility?
Perhaps use the recovery mode booting from a different disk.
This solved my problem.
Good luck.
 
gadgetfreak98 said:
My Accelsior completely died. Fortunately, I had a clone to an SSD, which I was able to flip over to. I cannot seem to do anything to resurrect the Accelsior, nor is it really accessible in Disk Utility. If anyone has any ideas about how I might try to resurrect it, by all means, please let me know.

Thank you.
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Assuming that the Accelsior S is showing up in System Info / PCIe cards . ." Link Width" . . I just fixed a problem with a Sapphire Dual-X showing Link Width of X8 instead of X16.

According to OWC the Accelsior S is X2 Link Width

My solution was
(1) Shut down - remove the power cord for one minute - remove all PCIe cards except your GPU - reboot with a PRAM reset.
(2) Shut down again - install your Accelsior S- if it shows up with the SSD - check the Link Width -should be X2 according to OWC.

Good Luck.
 
Deleting this post about the Accelsior S. Crashing has resumed this morning, so the Accelsior S wasn't the issue.
 
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