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kbmb
Aug 22, 2007, 08:35 PM
Was wondering, can the risers in the Mac Pro be switched from top to bottom or are the risers themselves tied to the slots they are in?

-Kevin


Fearless Leader
Aug 22, 2007, 08:37 PM
Why? Don't mess with it, there's no point.
SDAVE
Aug 22, 2007, 08:42 PM
I agree, Just do work on one riser at a time so you won't get them mixed up. I think they are the same, but I have doubts.
kbmb
Aug 22, 2007, 08:46 PM
Only reason I ask is because I was reading the How much memory thread here: http://forums.macrumors.com/showthread.php?t=344244

And per Multimedias post, I currently have my setup with 2x512 on Riser A and 2x1GB on Riser B. I'm going to switch them but was just curious whether I could just switch the risers themselves.

Guess I'll play it safe and switch the RAM.

Thanks.

-Kevin
Sean Dempsey
Aug 22, 2007, 10:11 PM
I swapped my risers yesterday, works fine for me.

I've heard of people doing this. I cannot possibly see why it would matter, they appear to be functionally identical.
SDAVE
Aug 22, 2007, 10:50 PM
Maybe each riser is identified differently? Dunno, I wouldn't take a chance on a working computer.
ZachPruckowski
Aug 22, 2007, 10:51 PM
It shouldn't matter if the 2x512 is in Riser A or B. Because it's quad-channel, they're accessed simultaneously. The graphics just show the most RAM on top because they need a convention for general sanity, as there are way too many combinations.
thxdave
Aug 22, 2007, 11:12 PM
Couldn't you look at the boards and see if there's a part number on them? If the number is the same, I can't imagine there would be any reason you couldn't switch them. After all, if you were putting in memory and had both boards out of the chassis, what would you do if you didn't remember which board came out of which slot?
kbmb
Aug 23, 2007, 08:10 AM
It shouldn't matter if the 2x512 is in Riser A or B. Because it's quad-channel, they're accessed simultaneously. The graphics just show the most RAM on top because they need a convention for general sanity, as there are way too many combinations.

Well, I'm going to go with what Multimedia said on the issue:
http://forums.macrumors.com/showpost.php?p=4075120&postcount=47

From what he's said and what I've read is that he's right.

-Kevin
Father Jack
Aug 23, 2007, 08:15 AM
Only reason I ask is because I was reading the How much memory thread here: http://forums.macrumors.com/showthread.php?t=344244

And per Multimedias post, I currently have my setup with 2x512 on Riser A and 2x1GB on Riser B. I'm going to switch them but was just curious whether I could just switch the risers themselves.

Guess I'll play it safe and switch the RAM.

Thanks.

-Kevin
Switch the ram, just in case, and remember the largest ram chips should be inserted into riser A in slots 1 and 2 (at the back) .. :)
kbmb
Aug 23, 2007, 08:19 AM
Switch the ram, just in case, and remember the largest ram chips should be inserted into riser A in slots 1 and 2 (at the back) .. :)

Switched the RAM...not the risers. I was just more curious than anything. Looking at the Risers, they looked identical....but I still played it safe and switched the RAM itself ;)

-Kevin
Father Jack
Aug 23, 2007, 10:34 AM
Switched the RAM...not the risers. I was just more curious than anything. Looking at the Risers, they looked identical....but I still played it safe and switched the RAM itself ;)

-Kevin
A wise move Kevin .. :)

Always make sure your largest ram sticks are inserted in the back slots in the top riser as they are addressed first. (or so I'm reliably informed) .. :cool:
flyinmac
Aug 24, 2007, 03:35 AM
Was wondering, can the risers in the Mac Pro be switched from top to bottom or are the risers themselves tied to the slots they are in?

-Kevin


I had the same question as you a couple of days ago.

I decided to open it up, and have a look for myself. Every component between the two risers (capacitors, resistors, various surface mount items, etc.) all matched exactly location for location.

So, then I compared the part numbers and all other numbers between the two risers. All the numbers matched.

So, then I swapped my risers, and the system has been working perfectly for 3 days now with the risers swapped.

I originally opted to leave the stock Apple memory inserted in it's original slots. Then added the new modules to the second riser card.

Then, I discovered the thing that indicated that the larger modules should go up-top (first riser). Whether there's anything to that, I don't know. I'd be interested in reading some real information instead of one guy's posting.

Anyway, rather than swap 4 modules (which means more risk for failing to seat a module properly), I opted to swap the risers.

No issues, no complaints. All is fine here.
anim8or
Aug 24, 2007, 03:52 AM
Only reason I ask is because I was reading the How much memory thread here: http://forums.macrumors.com/showthread.php?t=344244

And per Multimedias post, I currently have my setup with 2x512 on Riser A and 2x1GB on Riser B. I'm going to switch them but was just curious whether I could just switch the risers themselves.

Guess I'll play it safe and switch the RAM.

Thanks.

-Kevin

You are best to keep the larger RAM modules in the top riser (A), the risers are interchangeable so don't have any fear about switching them.

here is a nice little chart on how to arrange you memory according to sizes etc

http://homepage.mac.com/tribe3/.Pictures/MemConfig.jpg

Have fun!