MacPro 4,1 -> 5,1 possible 1333MHz configurations

If you want to get 1333MHz, you will need.

1) 5,1 firmware

2) 1333MHz RAM

3) CPU that support 1333MHz

So, in your case. You know that you can flash the firmware. You can buy the correct RAM. However, you have to upgrade the CPU as well in order to achieve that. If you really want to do this, please make sure you triple check how to do that. Upgrade the 8 cores 4,1 Mac Pro CPUs is not an easy job at all. It's not too hard to damage the CPU tray and brick your machine.

Anyway, you can run 3x16 or 6x8. Both options can give out 1333MHz. And both will run in triple channel if you install them in the right slots.

Yes, just check that, the X5570 is good for 1333MHz RAM.

In my own experience. Some RAM can run at 1333 even though you use all slots, and some other will down clock to 1066. Of course, when you use all slots, the computer can no longer take full benefit from the triple channel configuration.

Avery1 said:

Thanks for your reply. From what I am reading on the Intel site, that 2.93 core CPU already supports 1333MHz RAM... Please do let me know if you think that might have the incorrect info.

So, I can run at 1333MHz:
6x8
3x16
6x16

Any other configurations for future add-on to the 6x8 configuration that would also run at 1333?

Click to expand...

You are correct. The 4,1 Dual 8 core Mac Pro came with an option for 2.93GHz CPUs. These were X5570 and do support 1333MHz RAM. So yes, upgrading the firmware and using 1333MHz RAM will support the faster RAM speed. Since the CPUs utilize 3 channel RAM, optimum RAM speed will be obtained by leaving slots 4 and 8 MT, and populating only slots 1 thru 3 and 5 thru 7 with equally sized and specd RAM. In your case, that would be six 8GB RAM DIMMs available here:

http://www.datamemorysystems.com/dm61-769-x-3/

(2 of the above kits)

I would not populate only 3 of the slots.

Lou

flowrider said:

You are correct. The 4,1 Dual 8 core Mac Pro came with an option for 2.93GHz CPUs. These were X5670 and do support 1333MHz RAM. So yes, upgrading the firmware and using 1333MHz RAM will support the faster RAM speed. Since the CPUs utilize 3 channel RAM, optimum RAM speed will be obtained by leaving slots 4 and 8 MT, and populating only slots 1 thru 3 and 5 thru 7 with equally sized and specd RAM. In your case, that would be six 8GB RAM DIMMs available here:

http://www.datamemorysystems.com/dm61-769-x-3/

(2 of the above kits)

I would not populate only 3 of the slots.

Lou

Click to expand...

I may be wrong here, but are you sure the 4,1 - 2,93Ghz model is using x5670 CPU's?

I thought these were Westmere CPU's - thus only working if you upgrade the firmware. 4,1 -> 5,1

Edit: Yup, just checked. The 4,1 dual 2,93Ghz model used X5570 - not X5670. Maybe you just made a typo though, I don't know

MentalVizion said:

I may be wrong here, but are you sure the 4,1 - 2,93Ghz model is using x5670 CPU's?

I thought these were Westmere CPU's - thus only working if you upgrade the firmware. 4,1 -> 5,1

Click to expand...

No ! I'm owning one and it has 2x X5570's !

1333 MHz will work only as 1066 MHz despite the CPU supports it and firmware updated to 5,1. Apple blocked something inside the processor so if you use genuine Apple CPU's without heatspreader that RAM is limited to 1066 MHz.

If you replace them with non-genuine CPU's X5570's (with headspreader) or X5670/X5675's then RAM will be working as 1333 MHz.

Advantages of running RAM in triple channel

I am wondering if there are real world benefits of running RAM in triple channel? I have 8GBx3 in my 4.1 -> 5.1 Mac Pro. I was thinking of adding another 8GB stick in the last RAM slot to give 32GB. Not advisable? The RAM should still be running at 1333Mhz. no?

MentalVizion said:

I may be wrong here, but are you sure the 4,1 - 2,93Ghz model is using x5670 CPU's?

Click to expand...

Corrected - Fat Fingered it. I meant X5570

Lou

ShawnF said:

I am wondering if there are real world benefits of running RAM in triple channel? I have 8GBx3 in my 4.1 -> 5.1 Mac Pro. I was thinking of adding another 8GB stick in the last RAM slot to give 32GB. Not advisable? The RAM should still be running at 1333Mhz. no?

Click to expand...

I didn't see any performance drop after upgrading mine from 48 to 64 GB RAM.

CPU-Z under Windows still shows Triple Channel

Spacedust said:

I didn't see any performance drop after upgrading mine from 48 to 64 GB RAM.

CPU-Z under Windows still shows Triple Channel

Click to expand...

Sounds promising although it makes me wonder why I would still need triple channel? So I guess I can upgrade mine to 32GB in 8GBx4 arrangement without seeing any performance drops? I'm running a single X5670 CPU in my Mac Pro.

^^^^

http://macperformanceguide.com/Mac-Upgrade-MacPro-Memory.html

Channel 3 shares the third and fourth memory slot, IMHO, it's best to only use 3 or 6 slots with a triple channel memory CPU.

Lou

Spacedust said:

1333 MHz will work only as 1066 MHz despite the CPU supports it and firmware updated to 5,1. Apple blocked something inside the processor so if you use genuine Apple CPU's without heatspreader that RAM is limited to 1066 MHz.

Click to expand...

I have never heard of this limitation before. I find it hard to believe that Intel would allow Apple to modify something in the CPU to change the specifications of an Intel product without Intel giving it a different unique identifier.

Lou

ShawnF said:

I am wondering if there are real world benefits of running RAM in triple channel? I have 8GBx3 in my 4.1 -> 5.1 Mac Pro. I was thinking of adding another 8GB stick in the last RAM slot to give 32GB. Not advisable? The RAM should still be running at 1333Mhz. no?

Click to expand...

I've try both 8x3 @1333 CL9 and 8x4 @1066 CL7, can't feel any real world difference. Apart from less RAM may means less cache and more chance to use swap files.

Of course, I sm talking about normal ops, not any RAM bandwidth demanding, or benchmarking software. For those special case, the performance difference could be huge.

I'd love to go to 32GB (i currently have 3x8GB sticks) but am also worried about the speed reduction.

I use audio apps and memory speed (e.g. 1066 vs 1333) is often said to 'not make that much difference' - but for low latency audio performance in Logic/Pro Tools, it makes a big difference.

So, i am too 'scared' to drop in that 4th stick.

I basically figured that hopefully, in a year or so 48GB (3x16GB) would be a little more affordable.

Sharky II said:

I'd love to go to 32GB (i currently have 3x8GB sticks) but am also worried about the speed reduction.

I use audio apps and memory speed (e.g. 1066 vs 1333) is often said to 'not make that much difference' - but for low latency audio performance in Logic/Pro Tools, it makes a big difference.

So, i am too 'scared' to drop in that 4th stick.

I basically figured that hopefully, in a year or so 48GB (3x16GB) would be a little more affordable.

Click to expand...

Correct me if I'm wrong, but I think there is more advantage to the 25% extra RAM than the 2% drop in performance. I'm lucky that my 4,1 -> 5,1 Mac Pro happily runs @ 1333 with 4 x 8GB ECC RAM, but also keep in mind that if it drops to 1066, it also runs at a lower latency (the net effect being about equal). Higher memory clocks typically have higher latency timings. Lower memory clocks have lower latency. Those opposites tend to balance/cancel each other out. Some high performance RAM with super high clocks and very low latency specs are the exception.

From all I've ever read, the differences between 1066 and 1333 and 1600 and all the different latency timing specs is really only noticable in benchmarks. Like others have said, I don't think there is any real world difference. I'd say go for the 4th stick.

I'm not worried that adding a fourth stick will drop the speed to 1066 - more that the overall speed is reduced as slots three and four are shared. I was just using the 1066/1333 issue as an example that 'most people' say is going to have no impact on real world performance - however for audio, it has a real and measurable impact in real world usage and low latency benchmarks.

The extra 8gb only gives you a boost when working on the occasional projects that require more than 24gb of ram, whereas the reduced speed from the fourth stick is in effect all the time, from what I understand. Please let me know if the slowdown only occurs when the 4th ram slot is actually used (i.e. you're using more than 24gb of ram). So anyway, low latency performance is paramount with audio.

I push the single threaded performance quite a lot so for me, a few % difference matters. At least, I don't want to spend cash on another 8gb only to find that for the majority of projects/use, my system is slower.

So it all depends how much of a bottleneck the 24GB of ram is. I'm not paging out all the time, but having just upgraded to a 5,1/24GB, I was a bit annoyed to find one project use up all the ram - most are way below this though. Could even have been a memory leak in Logic X when doing a lot of pitch correction stuff.

Cheers

Ed

Just read this: http://macs.about.com/od/macupgrades/qt/2009-2012-Mac-Pro-Memory-Upgrades.htm

If you do choose to populate the last memory slots, you may reduce optimum memory performance, but only when memory in the shared slots is being accessed.

Click to expand...

So from what i can tell, if you have 4 x 8GB, the only downside is that if you go over 16GB of ram usage, the last 16GB is a bit slower (not just the last 8GB).

So to clarify, when using under 16GB, 'full speed' is maintained.

However, as the 2013 Mac Pro uses DDR 3 and has 4 slots, this is no different in the nMP either.

Sharky II said:

However, as the 2013 Mac Pro uses DDR 3 and has 4 slots, this is no different in the nMP either.

Click to expand...

AFAIK, the nMP has 4 channel for RAM, one channel for each stick.

Damn you're right! 4 slots gives you the best setup on a 2013.

Sharky II said:

However, as the 2013 Mac Pro uses DDR 3 and has 4 slots, this is no different in the nMP either.

Click to expand...

It is quite different. The nMP utilizes CPUs with 4 RAM channels vs. the 4,1 and 5,1 MPs that utilize 3 RAM channels.

Lou

trippel channel?

So if i use 16GB using all 4 slots what then, will my mac run faster (get a better geekbench result) than if i only use 3 slots getting 12GB? I do understand that my CPU has 3 memory channels, but will one channel be disabled if populate all 4 slots, or what?


---------
Macpro 4.1, Dualcore 2,66Ghz, Radeon 6870, having 16GB memory, using 2x 4TB Constellation ES3 in striping as bootdisk

Jahkir said:

So if i use 16GB using all 4 slots what then, will my mac run faster (get a better geekbench result) than if i only use 3 slots getting 12GB? I do understand that my CPU has 3 memory channels, but will one channel be disabled if populate all 4 slots, or what?

Click to expand...

I recently ran a few memory benchmarks on my single socket Mac Pro:

https://forums.macrumors.com/threads/1844436/

Jahkir said:

So if i use 16GB using all 4 slots what then, will my mac run faster (get a better geekbench result) than if i only use 3 slots getting 12GB? I do understand that my CPU has 3 memory channels, but will one channel be disabled if populate all 4 slots, or what?


---------
Macpro 4.1, Dualcore 2,66Ghz, Radeon 6870, having 16GB memory, using 2x 4TB Constellation ES3 in striping as bootdisk

Click to expand...

Keep in mind, performance is not measured by synthetic (Geekbench) benchmarks alone. Many people say benchmarks do not simulate real life application use, therefore are not a gauge for real life use. For instance, your applications may make better use of the extra RAM and give you better performance than with lesser RAM. Also, despite Geekbench numbers, you may not be able to even notice the slower speeds when using 4 channels of RAM. Factor in a fast SSD (XP941 or similar) and fast graphics, and you're probably not going to notice the "slowdown" when using 4 channels.