High-Density RAM not compatible?

Question

Level 1

5 points

High-Density RAM not compatible?

I have a dual 1.8ghz, early model with 8 ram slots. I ordered 2-1 GB RAM for it yesterday and just got the following message form the supplier. I should mention that the "low density" RAM he is now recommending is twice as expensive as the "high density" I have already paid for.

"After researching your motherboard, I found that it is incompatible with high density (128x4) ram and requires low density (64x8) ram. The specs and performance of these ram is exactly the same, the difference is the chip configuration (128x4 vs 64x8). I have these available in my store (The Memory Pro) as well if you're interested."

I've searched the database of this forum and all the comments I've come across seem to indicate that high density ram will work. ????

Power Mac G5, dual 1.8ghz (early model with 8 ram slots), Mac OS X (10.4.8)

Posted on Jun 22, 2007 10:50 AM

Reply

Answer 1

The hatter

Level 9

60,980 points

Jun 22, 2007 11:20 AM in response to Fay Krause

Head over to Crucial. Use their memory selector. Take a look at what they show for your 8-DIMM G5.

Seems like the vendor you chose is on the "marginal" side of Mac compatible G5 DDR400/PC3200 DIMMs.

http://www.crucial.com/mac/

Reply

Answer 2

Fay Krause Author

Level 1

5 points

Jun 22, 2007 11:36 AM in response to The hatter

Thanks Hatter. But I still see nothing on Crucial's website that says whether I can use high density or not. The memory I originally ordered is supposedly Samsung. Where did you find the info that the vendor is marginal?

Head over to Crucial. Use their memory selector. Take
a look at what they show for your 8-DIMM G5.

Seems like the vendor you chose is on the "marginal"
side of Mac compatible G5 DDR400/PC3200 DIMMs.

http://www.crucial.com/mac/

Reply

Answer 3

The hatter

Level 9

60,980 points

Jun 22, 2007 11:53 AM in response to Fay Krause

Crucial G5 1.8DP 8 slot

ALL of their memory is: 128Meg x 64

CT441517

2GB kit (1GBx2), 184-pin DIMM, DDR PC3200 memory module
CT441517 US $157.99

Module Size: 2GB kit (1GBx2)
Package: 184-pin DIMM
Feature: DDR PC3200
Specs: DDR PC3200 • CL=3 • Unbuffered
• NON-ECC • DDR400 • 2.6V • 128Meg x 64

And yes, there is DDR500 which does cost $100 more per 2 x 1GB kit.

So... again, who is trying to steer you to something you may not need? and for how much? and where?

Reply

Answer 4

Fay Krause Author

Level 1

5 points

Jun 22, 2007 12:04 PM in response to The hatter

Hatter, The message he sent was:

"After researching your motherboard, I found that it is incompatible with high density (128x4) ram and requires low density (64x8) ram. The specs and performance of these ram is exactly the same, the difference is the chip configuration (128x4 vs 64x8). I have these available in my store (The Memory Pro) as well if you're interested."

You say that all of Crucial's memory is "ALL of their memory is: 128Meg x 64"

I don't understand how this correlates one way or the other with 128x4 or 64x8.
"The Memory Pro" is a big time operator on EBay with tens of thousands of transactions...but I still don't trust that my original purchase won't work. What exactly does high density or low density mean. Isn't it simply a measure of how many chips (either 4 or 8) there are on each dimm?

Crucial G5 1.8DP 8 slot

ALL of their memory is: 128Meg x 64

CT441517

2GB kit (1GBx2), 184-pin DIMM, DDR PC3200 memory
module
CT441517 US $157.99

odule Size: 2GB kit (1GBx2)
Package: 184-pin DIMM
Feature: DDR PC3200
Specs: DDR PC3200 • CL=3 • Unbuffered
• NON-ECC • DDR400 • 2.6V • 128Meg x 64

And yes, there is DDR500 which does cost $100 more
per 2 x 1GB kit.

So... again, who is trying to steer you to something
you may not need? and for how much? and where?

Reply

Answer 5

The hatter

Level 9

60,980 points

Jun 22, 2007 12:12 PM in response to Fay Krause

What I saw on that page was that all 1GB DIMMs were 128 x 64.

When I was buying for my G4 MDD Crucial was experimenting it seems with the number of DIMMs on each chip and had problems with some configurations. If Crucial says something works, though, I tend to trust them more than anyone else.

Did you read through? I didn't post link for fun or to waste my time and yours.

The number of black components on a 184-pin DIMM can vary, but it always has 92 pins on the front and 92 pins on the back, for a total of 184. 184-pin DIMMs are approximately 5.25 inches long and 1.25 inches high, though the heights can vary. While 184-pin DIMMs and 168-pin DIMMs are approximately the same size, 184-pin DIMMs have only one notch within the row of pins.

Mac Pro 2GHz 4GB 10K Raptor Cinema HD Mac OS X (10.4.10) WD RE RAID Aaxeon FW800 PCIe Sonnet Tempo APC RS1500 Vista

Reply

Answer 6

Fay Krause Author

Level 1

5 points

Jun 22, 2007 12:25 PM in response to The hatter

I apologize for wasting your time, but I did read the article you linked to, and, I repeat, it does not mention the issue of high (128x4) or low (64x8) density, i.e. 128x64 is not the same as 128x4.

What I saw on that page was that all 1GB
DIMMs were 128 x 64.

When I was buying for my G4 MDD Crucial was
experimenting it seems with the number of DIMMs on
each chip and had problems with some configurations.
If Crucial says something works, though, I tend to
trust them more than anyone else.

Did you read through? I didn't post link for fun or
to waste my time and yours.

The number of black components on a 184-pin DIMM
can vary, but it always has 92 pins on the front and
92 pins on the back, for a total of 184. 184-pin
DIMMs are approximately 5.25 inches long and 1.25
inches high, though the heights can vary. While
184-pin DIMMs and 168-pin DIMMs are approximately the
same size, 184-pin DIMMs have only one notch within
the row of pins.

Mac Pro 2GHz 4GB 10K
Raptor Cinema HD Mac OS X (10.4.10) WD
RE RAID Aaxeon FW800 PCIe Sonnet Tempo APC RS1500
Vista

Reply

Answer 7

Jun 22, 2007 7:38 PM in response to Fay Krause

I believe Memory Pro is incorrect. I went through all the PDFs for Power Macs on the Apple website. While I did not find the Dual 1.8 with 8 slots mentioned in any of them, I did see that, in every case, they were listed as being compatible with DIMMs with 128Mbit and 256Mbit memory.They may simply have given you bad memory. If you wish, you can find the specifications on the bottom half of the PDFs, on the left side.

Reply

Answer 8

linuxuser

Level 3

680 points

Jun 22, 2007 10:41 PM in response to Fay Krause

If it is one of the Powermac G5s that take PC3200 ram, then YES they will take high density ram.

Reply

Answer 9

myhighway

Level 5

7,270 points

Jun 23, 2007 12:41 AM in response to Fay Krause

The memory I originally ordered is supposedly
Samsung.

Are the entire modules made by Samsung, or only the component chips?

Also, have you reviewed any of the eBay Buyers' Guides on DDR memory for answers to your questions?

What I read there is that 128x4 isn't fully compliant with JEDEC specifications, as the 64x8 is.

Reply

Answer 10

japamac

Level 7

24,400 points

Jun 23, 2007 3:57 AM in response to Fay Krause

Hi-

What does high density and low density memory mean?

The density of a memory module refers to the number of the chips that are on the module. Different computers require the memory module to be built with a different number of chips. i.e. There is more than one way to build a 128MB or 256MB memory module.
When a RAM module is built, the manufacturer can design it using high
density or low density chips. For example, modules built with 4 x 32Mb chips (high), 8 x 16Mb chips or 16 x 8Mb chips (low)- all come out to the same amount of RAM.
However, the memory controller circuit in a computer must be able to address the chips on the module - if the memory controller cannot address higher density chips, that computer will only function with modules built with lower density chips.
The following may provide you with some insight:

http://reviews.ebay.com/Myth-Low-Density-vs-High-Density-memory-modules_W0QQugid Z10000000001236178

It's always best to buy your RAM from someone who KNOWS Mac's. Crucial, or OWC:

http://eshop.macsales.com/MyOWC/Upgrades.cfm?model=206&type=Memory&TI=4510&shoup grds=Show+Upgrades

Low density has a higher compatibility rate than high density. High density is cheaper, but not necessarily better.
In my G4, I have had problems with high density, and no problems with low density.

G4AGP(450)Sawtooth, 2ghz PowerLogix, 2gbRAM, 300gbSATA+160gbATA, ATI Radeon 9800 Mac OS X (10.4.8) Pioneer DVR-109, ExtHD 160gb x2, 23"Cinema Display, Ratoc USB2.0, Nikon Coolscan

Reply

Answer 11

The hatter

Level 9

60,980 points

Jun 23, 2007 6:02 AM in response to japamac

PowerMac G5 - RAM Expansion Specifications

Reply

Answer 12

myhighway

Level 5

7,270 points

Jun 23, 2007 8:32 AM in response to myhighway

Looking at the Samsung website this morning, specifically at the 1GB PC3200 DDR400 RAM modules that Samsung produces, the modules all appear to be low-density modules, with a total of 16 component chips, 8 on each side of the module.

If high-density Samsung RAM is being offered for sale, such modules are not actually manufactured by Samsung, although the black component chips attached to the module may have been. Samsung does not make 2GB PC3200 DDR400 modules, and I've never seen or heard of any, so it's not like someone can just duplicate one side of a Samsung two-sided module. In other words, an assembler of such a module will not even be able to try to copy a Samsung design, since there has been none, and Samsung's been making PC3200 DDR400 for a long time.

Such high density modules will not actually meet Apple's exacting specifications, or the specifications of most other computer makers. Whether such modules will work or not, and for how long, is open to question. That's why they can be bought so inexpensively:) and that's why your good, honest seller would rather not sell them with a warranty for use in your Power Mac.

edit-
While the price may be higher than you wish to spend, the current price is a bargain compared to what it was at the time your Power Mac was made in late 2003-early 2004.

Message was edited by: myhighway

Reply

Answer 13

Fay Krause Author

Level 1

5 points

Jun 23, 2007 9:24 AM in response to The hatter

Hatter, Thank you for this informative link. I also thank everybody else for their info. I have cancelled the high density ram order and will purchase low density ram from a more reliable source.
Thanks to all again.

Reply

Answer 14

Fay Krause Author

Level 1

5 points

Jun 25, 2007 1:05 PM in response to Fay Krause

Sadly, several hours after I emailed Memory Pro that I wanted to cancel the order, I received an email that it had already been shipped. So...could it be dangerous to my computer to even try to install and use it??

Hatter, Thank you for this informative link. I also
thank everybody else for their info. I have
cancelled the high density ram order and will
purchase low density ram from a more reliable
source.
Thanks to all again.

Reply

Answer 15

myhighway

Level 5

7,270 points

Jun 25, 2007 2:59 PM in response to Fay Krause

Don't worry, it might work (some do), or it might not, or it might be only partially recognized by your Mac.

These are things that can, and do, happen occasionally in the normal course of business, when either incorrect or flawed RAM gets shipped to a buyer. Trying it won't cause any problem with your Mac, won't cause a problem for the RAM, and mainly causes you some frustration from making the return to the seller.

Reply