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MikeymikeT5

macrumors member
Original poster
Mar 9, 2016
48
7
Good afternoon,

I've been trawling this forum for all sorts of guidance, and hoping that some of you guys can help?...

I have an old 3,1 2.8 8 core machine here which I have had for many years, inside which I have an OWC Accesior PCI card, with Crucial 500GB SSD mounted to it. This is running El Capitan, and has all my apps installed on it.

I also have three conventional hard discs inside this machine, with all my docs, photos, etc...

Yesterday, I picked up a 5,1 system, 3.33GHz 12 core, with GTX680 (2GB), and 32GB of ram (4GB modules). It has two hard drives installed, and is running Sierra.

Firstly, can I simply pull the OWC card and SSD from the old machine, put it in the new one, and boot up from it, and after that upgrade to Sierra? Should I also move my other hard drives over at the same time? Is it also best to put this SSD and card into PCIe slot 3 or 4? I always assumed these were the fastest, but have this morning read conflicting opinions to that on another thread.

Lastly, will changing the 8 x 4GB memory modules for 6 x 8GB ones (48Gb total) give me any more performance?

Many thanks in advance for any advice you guys and gals can offer...

Mike.
 
You may need to install OS on another disk and then use migration assistant to import your data.

I just went through this moving from 2010 MBP to 2012 MBP. The 2012 would not boot from the drive (via USB).
 
Yes, you should able to pull all your hard drive (not SSD and HDD) from 3,1, install them into the 5,1, and they should work straight away.

For PCIe SATA III card, doesn't really matter, any slot on the 5,1 has enough bandwidth for that. And NO, the fastest slots are slot 1 and 2, they are both PCIe 2.0 x16 slot (independent). Slot 3 and 4 actually share the same PCIe 2.0 x4 lane, much slower than slot 1 or 2.

If you rarely can use more than 32 GB RAM, make it 48 won't dramatically improve anything. I found that my general RAM usage is about 24GB, no matter I have 4x8GB, or 3x16GB, performance for most general stuff are more or less the same. However, I can clearly see that the system use the remaining RAM as cache, which actually speed up some process a bit, sometimes avoid I/O congestion, or avoid the need to read from the slow HDD again (for the same data).

E.g. I want to remux a 5GB video. If I do that on my SSD, since I do read / write at the same time, the actual write speed can only be about half of the max. But let's say after remux, during testing, I want to fine tune the sound track time stamp, and remux the same video again. Since all data already stored in the RAM. Now the 2nd time can write 2x faster than the first time (No read, but pure write to the SSD).

So, it's really depends on your work flow. If you keep working on different data, and usually use those data only once during the workflow, then more RAM as cache won't help much.

But if you usually keep working on the same data set for a period of time, then yes, more RAM should able to give you better performance.
 
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Yes, you can plug your SSD PCIe card into any PCIe slot and you should be able to boot up with no issues. As explained above Slots 1 & 2 are X16 and Slots 3 & 4 are X4, all four are PCIe spec 2.0. You should be able to upgrade to Sierra without issue. I'm running my boot SSD in slot 4 as it has plenty of band width to handle my SM951 SSD.

As far as the hard drives go, moving them over is also fine, but the sleds are different from a 3,1 to a 5,1 cMP. You will need to remove the HDDs from your old sleds and attach them to the sleds on the 5,1.

As for the RAM. You may see some improvement in speed, very slight. The 5,1 uses 3 channel RAM and right now you are using all 3 channels, but slots 3&4 and 5&6) are tied together and when both are populated performance tends to suffer. Not by much, but it is less than ideal. Why Apple did this, I will never know. Using all three channels (slots 1-3 and 4-6) is the ideal RAM population for a 4,1 or 5,1 cMP.

Lou
 
I moved from a 3,1 to a 5,1 in the spring. My two PCIe SSDs worked fine and I was able to boot off them. I actually found that they were a bit faster. I’d benchmarked them in the 3,1 with xbench and got a much better score in the 5,1
 
Yes, you can plug your SSD PCIe card into any PCIe slot and you should be able to boot up with no issues. As explained above Slots 1 & 2 are X16 and Slots 3 & 4 are X4, all four are PCIe spec 2.0. You should be able to upgrade to Sierra without issue. I'm running my boot SSD in slot 4 as it has plenty of band width to handle my SM951 SSD.

As far as the hard drives go, moving them over is also fine, but the sleds are different from a 3,1 to a 5,1 cMP. You will need to remove the HDDs from your old sleds and attach them to the sleds on the 5,1.

As for the RAM. You may see some improvement in speed, very slight. The 5,1 uses 3 channel RAM and right now you are using all 3 channels, but slots 3&4 and 5&6) are tied together and when both are populated performance tends to suffer. Not by much, but it is less than ideal. Why Apple did this, I will never know. Using all three channels (slots 1-3 and 4-6) is the ideal RAM population for a 4,1 or 5,1 cMP.

Lou
What about a ssd in the optical bay - is that as fast as slot 1&2 or like slots 3-4?
 
Thanks for the advice Gents, all went well, aside only from the Photos app doing it's whole files processing thing. I guess that'll take another day or so to complete itself.

Am I better off buying another SSD and PCIe card, and creating a fusion drive with the 4TB WD Gold disc that I have in there? Would like to make this thing as fast and smooth as I possibly can...
 
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