ECC memory on AGP PowerMac G5?

[MacPro2006VBox]

It got me thinking… the Mac Pro uses ECC memory…. What if we could double our G5’s by using ECC DDR (as long as it’s unbuffered like the regular stuff). Just imagine it…. 8 or 16 gigabytes of DDR memory for our AGP PowerMac G5’s, and 4 gigabytes for the equivalent iMac G5!

 

[Project Alice]

It got me thinking… the Mac Pro uses ECC memory…. What if we could double our G5’s by using ECC DDR (as long as it’s unbuffered like the regular stuff). Just imagine it…. 8 or 16 gigabytes of DDR memory for our AGP PowerMac G5’s, and 4 gigabytes for the equivalent iMac G5!

I thought about trying this. One of these days I'll buy a couple 2GB DDR ECC unregistered sticks and see what my PM7,2 thinks of them.

But I won't be able to do so for awhile; probably a month or so. Having some financial and vehicle trouble at the moment.

 

[Tratkazir_the_1st]

BTW, at least PM with DDR2 can use both kinds of memory.

 

[JohnKCG]

Perphaps this is the correct thread to post and ask this, but as a quad owner, I investigated to see which memory is compatible with the memory controller (no idea if it's the same on earlier G5 models...) and I believe I may have reached a conclusion, in one hand, the IBM memory controller PDF says that ECC registered memory is supported, but what isn't supported (according to users here) is buffered memory, in theory, you could use Registered ECC as long as it isn't buffered, but don't take my word for granted..

IBM 44T1547 16GB (2X8GB) 533MHZ PC2-4200 140-PIN CL4 ECC REGISTERED DDR2 SDRAM 883436050173 | eBay

Find many great new & used options and get the best deals for IBM 44T1547 16GB (2X8GB) 533MHZ PC2-4200 140-PIN CL4 ECC REGISTERED DDR2 SDRAM at the best online prices at eBay! Free shipping for many products!

www.ebay.com

That link has a 8gb ECC ddr2 pc2-4200 registered stick, it's expensive yes, but what we don't know ifsaid memory is also buffered or not, if it isn't buffered and someone here have access to it, it could be interesting to see if a G5 supports it, if it does, the premise of a 64gb ECC G5 may be doable, if it isn't, there is another option I found:

A-Tech 8GB (2x4GB) RAM for Intel SS Series SSR212MA | DDR2 800MHz ECC RDIMM PC2-6400 2rx4 Registered DIMM Server Memory Kit

A-Tech 8GB (2x4GB) RAM for Intel SS Series SSR212MA | DDR2 800MHz ECC RDIMM PC2-6400 2rx4 Registered DIMM Server Memory Kit

www.amazon.com

There are other options in that publication, but note that they don't specify if it's buffered or not, yes, its ecc registered, but the IBM PDF says registered its supported... Maybe it works or maybe it doesn't...

 

[Tratkazir_the_1st]

AFAIK, G5 Quad without some firmware modifications supports only 16 Gb with 2Gb modules. I will wonder if it would "eat" that kind of RAM at all . Kingston KVR533D2E4/1G - works for granted. There are 2G modules, you can try to find them. But 8Gb. You can get pair of them & try .

 

[JohnKCG]

Well, there is this:

https://www.reddit.com/r/mac/comments/1y5pvx

The key point is that he used Udimms, which may refer to unregistered or unbuffered, however, the IBM docs tell us that registered is okay but experience of users tend to say buffered its not, so we are on a weird spot where registered unbuffered ECC could be possible, but to my knowledge no one has ever made that kind of tests...

 

[Tratkazir_the_1st]

"Udimm" usually means "unbuffered". Someone could say about that picture - "Photoshop!!!" Anyway, I'd like to have so much ram for my Quad - Gentoo likes RAM (for some large packages it can be reconfigured as tmpfs) & cores . Anyway, interesting topic.

 

[Tratkazir_the_1st]

Technical Q&A QA1099: Reducing the size of Physical Memory in Open Firmware

QA1099: Describes how to configure the Power Macintosh so less memory is recognized than is actually present.

developer.apple.com

That's quite opposite, but m.b. interesting. Can you please drop some links about IBM CPC945? (is it memory controller in G5?)

 

[JohnKCG]

Of course:

http://datasheet.datasheetarchive.com/originals/library/Datasheets-SW3/DSASW0048084.pdf

It came from there:

A little G5 Quad KVM fun......

Some interesting stuff in there, first...... Then..... So with a little tinkering on the I2C bus we should be able to yield a 1334Mhz system bus and 2,7Ghz CPU speed........................

forums.macrumors.com

In any case, I believe it is the memory controller for the Quad, I'm not aware if it's also the MC for other G5's but a starting point as good as any nonetheless

 

[Tratkazir_the_1st]

" 64 GB max capacity using 4 pairs of 8 GB double-sided DIMMs. (Only 62 GB addressable due to 2 GB
I/O hole.)"
But it is feature of CPC945. Who knows, how Apple designed the board...

 

[JohnKCG]

true, Apple could have crippled the board or disabled it via software... but it might be doable, given that someone has a pair of those 8gb dimms, in any case, AFAIK the known and tested limit of ECC ram is 16g of 2gb sticks while the one for non ecc is 32gb of UDIMMS as said earlier, if more ram can be slotted (while it seems possible) is unknown, only a tester with more or less deep pockets should be able to say for sure...

Off topic, you run gentoo? how does it work on G5s? I heard that installing PPC64 SUSE Tumbleweed is possible on G5s, giving you a much more supported and stable OS.

 

[Tratkazir_the_1st]

Gentoo itself runs like other linux distro . When compiled (USE flags & not too large supported package base makes it a bit troublesome ). About SuSE - ********, more or less current version can not be installed from their installers, Yast don't knows about Apple Partition Map. Personally I didn't find a way to instal it to GPT AND boot afterwards. By some unknown reason GRUB2 from other linuxes on my Quad detects only his own hard drive (I've installed SAS card & enclosure for 4 2,5" drives (SSD\HDD, full height), you can look for my topic about it here).

 

[Tratkazir_the_1st]

BTW, download User Manual for CPC945 & read from page 132. You'll find a bit more info about supported memory (some of this info confuses me). Take close attention to Table 7-1.

 

[JohnKCG]

Gentoo itself runs like other linux distro . When compiled (USE flags & not too large supported package base makes it a bit troublesome ). About SuSE - ********, more or less current version can not be installed from their installers, Yast don't knows about Apple Partition Map. Personally I didn't find a way to instal it to GPT AND boot afterwards. By some unknown reason GRUB2 from other linuxes on my Quad detects only his own hard drive (I've installed SAS card & enclosure for 4 2,5" drives (SSD\HDD, full height), you can look for my topic about it here).

Perphaps if you follow this guide:

1079435 – cannot install on PowerMac G5 - yast requires a PReP partition on non-PReP compliant system

bugzilla.suse.com

you may be able to sucessfully install Tumbleweed? I need to service my quad's LCU before using it so I can't test it myself.... in any case, that guide seems horribly lenghty so it's not attractive... But Tumbleweed looks like the best supported distro for pre little endian POWER, so it may be worth the effort...

 

[JohnKCG]

BTW, download User Manual for CPC945 & read from page 132. You'll find a bit more info about supported memory (some of this info confuses me). Take close attention to Table 7-1.

If I have to bet, those 128 bit modules (that to my knowledge only exist soldered on GPUs), whatever they are, are like this:

Centaur - IBM - WikiChip

Centaur is a memory buffer chip designed by IBM for their POWER scale-up microprocessors. First introduced with the POWER8 microarchitecture, each Centaur chip includes 16 MiB of eDRAM and four DDR3/DDR4 DRAM ports.

en.wikichip.org

Something extremely obscure and hard to find (if even possible), so no.... I don't think it is something to bother thinking....

Now, according to wikipedia:

DDR2 SDRAM - Wikipedia

en.m.wikipedia.org

The max size of commercially available DDR2 DIMMS is 8GB, which makes sense since the IBM module I shared earlier is 8GB, I also believe it to be unbuffered (which makes sense since it's IBM memory, but even then it could be buffered for Intel servers...), so now we know that the memory controller in the Quad is theoretically capable of handling single 8GB DIMMS of unbuffered registered ECC DIMMS (if those even exist... I bet they are the ones I posted above, there are a lot of buffered ones (those make possible to have 64GB of ECC on a Mac Pro 2006/2007 IIRC)), now the question is, did Apple cripple the capabilities of the MC on purpose? Did they do it via Software or Hardware? I wonder if someone is able to answer such questions.......

 

[Tratkazir_the_1st]

unbuffered registered

AFAIK - memory module have to be registered OR unbuffered. Not both. Anyway all this theoretical ideas can only be proven by experiment . And according to everymac.com, some of RAM limitations as they are specified by Apple (in some models) can be overcome by installing modules with maximum capacity.

 

[JohnKCG]

Afaik, the Buffered moniker was made by Intel... Hence the incompatibility with the G5..

 

[B S Magnet]

Well, there is this:

https://www.reddit.com/r/mac/comments/1y5pvx

The key point is that he used Udimms, which may refer to unregistered or unbuffered, however, the IBM docs tell us that registered is okay but experience of users tend to say buffered its not, so we are on a weird spot where registered unbuffered ECC could be possible, but to my knowledge no one has ever made that kind of tests...

Ah. Another gem by the notorious rabidz7, smdh.

 

[MacPro2006VBox]

I found this stuff on Amazon.... unsure if it’d work or not in an AGP G5:

Those prices though...... I hate those types of people or those type of listings if they clearly have it in stock.

 

[JohnKCG]

IIRC, ddr1 isn't interchangeable with ddr2 so I would say no, it won't work, in any case, which Mac G5 do you have exactly, use this list to guide yourself:

Apple Power Mac G5 Specs (All Power Macintosh G5 Technical Specs): EveryMac.com

Technical specifications for the Apple Power Macintosh G5 series. Dates sold, processor type, memory info, hard drive details, estimated retail prices, and more.

everymac.com

 

[LightBulbFun]

figured id insert some bits that I have posted on this forum before people end up spending far too much money on RAM that wont work in their systems!

according to the "U4" IBM CPC945 Memory controller datasheet, it can work with up to 64GB of RAM (with a 2GB hole right at the end)

however from what iv read 4GB RAM sticks while will work PCIe G5 for 32GB but only 16GB is seen by OS X

iv also read of a way around that, but considering who it was from, im taking it with a very large pinch of salt until im able to verify it myself

I do have some 4GB DDR2 UDIMM RAM sticks, however sadly they are a type of Samsung stick that none of my PowerPC macs seem to like (I have ones in smaller size ones in SODIMM form factor that my DLSD complains about in the same way)

(BTW do you mean Gb (Gigabit) or GB (Gigabyte) ? )

they did make 2GB DDR1 UDIMMs but they are stupidly rare

the Later revision of the Xserve G5 was compatible with them

(and indeed I suspect PowerMac G5s, if you go through the About this Mac thread in the Photos section of this forum, someone posted a 2.7Ghz G5 with 16GB of RAM, and I know the later G5's use the same U3 heavy North bridge/memory controller that the Xserve G5's use)

I would love to find some to try in my PowerMac G5 and Mac Mini but I have not been able to find any

Kingston made a kit KTA-G5400E/4G for the Xserve which was 2x2GB ECC UDIMMs sticks for example

but I have literally never seen any for sale on ebay etc, there where also some other 3rd party 2GB ECC and non ECC UDIMMs, but those are just as rare, and what few places I can find with them listed want like $70-140 a stick

(being UDIMMs the ECC part is not a problem thankfully, Uninorth macs will work fine with ECC UDIMMs, they will just ignore the ECC bit, its RDIMMs they dont work with)

the TL;DR is

if you have a PowerMac G5 with the U3 Heavy Memory controller then you may be able to get away with 2GB DDR1 UDIMMs but said RAM sticks are incredibly rare, they CAN be ECC but they CANNOT be registered ram sticks


on the PCIe G5 front, the correct 4GB DDR2 RAM sticks may work, but only 16GB of RAM will be used by OS X, however again very few people have done this so the details are not very well known

 

[JohnKCG]

I expected OS X to behave like that with ram.. Since I use Linux with powermacs the extra 16gb should be recognized and used, in any case,what do you think of the IBM 8GB per stick I posted earlier? A little off topic now that I know you have a DLSD PB, have you upgraded the WiFi card on it ? I wonder if the airport card slot can be used with a more modern mpcie or m2 WiFi card with an adapter, also, can you use faster ram than 4200?

 

[Tratkazir_the_1st]

but only 16GB of RAM will be used by OS X

There can be other OSes in G5 .

 

[B S Magnet]

A little off topic now that I know you have a DLSD PB, have you upgraded the WiFi card on it ? I wonder if the airport card slot can be used with a more modern mpcie or m2 WiFi card with an adapter, also, can you use faster ram than 4200?

By the sound of it, you have never dealt with a DLSD PowerBook before.

The first thing you need to know about the final run of PowerPC Macs is they used an integrated wifi/bluetooth module for the first time. Note I said “module” and not “card”. It isn’t PCIe. It also has its own cable connecting receptacle variations, depending on whether it’s designed for the iBook, the PowerBook, the iMac, or the Power Mac multicore models. It looks generally like this, with the left area varying:

The only way you can bump a PowerPC Mac to something beyond 802.11g is to find an 802.11n Cardbus/PCMCIA card and use the slot on a PowerBook 15" or 17", or by adding a PCI/PCIe 802.11n wifi card to a Power Mac G5. I’ve done both.

 

[JohnKCG]

I see...

By the sound of it, you have never dealt with a DLSD PowerBook before.

The first thing you need to know about the final run of PowerPC Macs is they used an integrated wifi/bluetooth module for the first time. Note I said “module” and not “card”. It isn’t PCIe. It also has its own cable connecting receptacle variations, depending on whether it’s designed for the iBook, the PowerBook, the iMac, or the Power Mac multicore models. It looks generally like this, with the left area varying:

View attachment 1795674

The only way you can bump a PowerPC Mac to something beyond 802.11g is to find an 802.11n Cardbus/PCMCIA card and use the slot on a PowerBook 15" or 17", or by adding a PCI/PCIe 802.11n wifi card to a Power Mac G5. I’ve done both.

And you are right, I haven't dealt with a DLSD yet, I will pick one (hopefully) tomorrow, but since I intend to max it out right from the start, I thought it would be a good idea to come here and ask about options...

Since you have experience with this kind of thing, If I remove the internal Wi-Fi module but plug a cardbus wifi card, I will still have wifi, right? not using the internal card shouldn't improve things drastically since I don't think it consumes much power or generates heat, but every little improvement is appreciated...