I can easily predict what will be your next move. You will replace the 512 MB DIMM by a 1 GB DIMM for a total of 2 GB.
In the PC world there is a huge difference between single and double channel memory bus : expect a 5-10 % speed bump.
Thanks for the very helpful reply.
The developer's note also points out: "The iMac G5 supports CAS latencies of 2, 2.5, 3, 4, and 5."
This all begs the question: what are the exact specs of the Apple memory? If we buy a 512KB machine and then add a 512KB memory stick from a third-party vendor, I assume that we need to match the speed (CL-3 / CL-2.5 / CL-2) in order to get the dual memory bus benefit. Is Apple's RAM prices (and Kingston's) more expensive because it is faster -- and matches Apple's stock RAM?
We may have to wait for first shipments to arrive to sort it out, but for the time being, Crucial offers only CL-3 RAM for the G5 iMac. Kingston's iMac RAM is way more expensive. Given that they the only ones on the ball enough to point out the single / double memory bus issue, might this indicate that Kinston's RAM is more expensive because it is faster.
Of course all this begs another question: if Apple and Kingston's RAM is faster than CL-3, if I put in two 3rd party CL-3 sticks will I experience a performance hit compared to if I used faster memory?
I fully acknowledge that this subject doesn't really make sense in the context of an iMac ("if you are concerned about small incremental speed bumps, dude, you really should just buy a dual PowerMac...").
It's just that given that I am buying an iMac, I'm looking for the price/performance sweet spot...
Not to add undue complexity, but there are obviously different types of RAM out there for any given size. Crucial offers only CL-3 RAM for the G5 iMac. Kingston's is way more expensive (although they are the only memory vendor on the ball enough to point out the single / double memory bus issue).
Once we set up the computer to have access to a double memory bus instead of single, is there any ADDITIONAL benefit in considering faster (CL-2 or CL2.5) memory?
I fully acknowledge that this question doesn't really make sense in the context of an iMac ("if you are concerned about small incremental speed bumps, dude, you really should just buy a dual PowerMac...").
It's just that given that I am buying an iMac, I'm looking for the price/performance sweet spot...
I don't think that the latency will do a huge difference on Macs. Macs have autodetect feature, and know automatically what kind of Ram latency the DIMM have. If you have one CL3 DIMM, and one CL2 DIMM, the mac, will use the CL3 mode. So if you want the maximum speed, you can choose to go to CL2 DIMM in each slots, but it will be an expansive option and nothing prove that it will gie you a huge benefit.
It's strange that Apple has never really communicate on this point, at the contrary of the PC world where you will find tons of articles about this subject. Perhaps Apple consider that the latency thing do not bring sustantial additional benefit.
Not to add undue complexity, but there are obviously different types of RAM out there for any given size. Crucial offers only CL-3 RAM for the G5 iMac. Kingston's is way more expensive (although they are the only memory vendor on the ball enough to point out the single / double memory bus issue).
Once we set up the computer to have access to a double memory bus instead of single, is there any ADDITIONAL benefit in considering faster (CL-2 or CL2.5) memory?
I fully acknowledge that this question doesn't really make sense in the context of an iMac ("if you are concerned about small incremental speed bumps, dude, you really should just buy a dual PowerMac...").
It's just that given that I am buying an iMac, I'm looking for the price/performance sweet spot...
No need to buy faster timed memory... not enough of a price/performance bump. Some CL 2.5 isn't much more expensive than CL3, so that might be worth it. It's about a 2% performance bump from 3 -> 2.5, and 2% from 2.5 -> 2.
Given all this, I just can't believe that Apple doesn't say something like:
"While the iMac G5 accepts any combination of DDR400 (PC3200) SDRAM in its two slots, a matched pair will modestly boost performance."
... but again, I guess this is not a PowerMac, and 99.9% of iMac users will never notice or care.
Actually, Apple did say this today. If you have mismatched pairs, then the bus speed is 64. If the pairs are matched, the bus speed is 128.
So... Here's a question: The iMac comes with 256. If you add another 256, will the performance of the machine be better or worse than if you had added a mismatched 512? In other words, would 512 at 128 be better than 768 at 64 (assuming that you don't ever move into virtual memory with either configuration)?
Actually, Apple did say this today. If you have mismatched pairs, then the bus speed is 64. If the pairs are matched, the bus speed is 128.
So... Here's a question: The iMac comes with 256. If you add another 256, will the performance of the machine be better or worse than if you had added a mismatched 512? In other words, would 512 at 128 be better than 768 at 64 (assuming that you don't ever move into virtual memory with either configuration)?
I doubt the boost of having syncing pairs of RAM would offset the 256MB of less RAM. I would always go with the higher RAM.
So identical DIMM means any two PC3200 (400MHz) DDR SDRAM DIMMs of equal size (512+512, etc.), regardless of the vendor?
Its more than just MB size though. the memory timing/latency must be identical for the sticks as well. most quality ram has this onthe sticker on the front and may appear as 2/2/4.5 or some combination of numbers. your best bet is to get two matched pairs to ensure you run in 128bit mode.
Its more than just MB size though. the memory timing/latency must be identical for the sticks as well. most quality ram has this onthe sticker on the front and may appear as 2/2/4.5 or some combination of numbers. your best bet is to get two matched pairs to ensure you run in 128bit mode.
Is the standard apple ram module marked with identifying information (ie "sticker on the front")which will allow us to match the specs? If not, can we get the info from apple? It's obviously not a big deal, but if one can match a memory stick and get 128bit, that seems a worthwhile thing to do. I ordered with a 512k stick and planned to add an aftermarket 512 or 1 Gg. I guess I could sell the 512k that came in the machine and replace with matched sticks. What do you think?
Is the standard apple ram module marked with identifying information (ie "sticker on the front")which will allow us to match the specs? If not, can we get the info from apple? It's obviously not a big deal, but if one can match a memory stick and get 128bit, that seems a worthwhile thing to do. I ordered with a 512k stick and planned to add an aftermarket 512 or 1 Gg. I guess I could sell the 512k that came in the machine and replace with matched sticks. What do you think?
buzz
Fiscal rule of thumb that bears reiterating: purchase hardware from Apple with the lowest amount of RAM possible for that machine, then purchase additional memory from a third-party, such as Crucial.com, RamJet.com, etc. You'll save some cash. (Incidentally, are you purchasing an iMac? They come stock with 256 MB.)
I can't say for certain, but doesn't the system profiler in OS X provide details such as latency, etc., for the memory?
Incidentally, are you purchasing an iMac? They come stock with 256 MB.)
I ordered a 20" with 512k, thinking I would buy another 512K online somewhere. I'm currently using a peecee so I don't know about OSX system profiler yet.
No problems. We fired up Photoshop, Vectorworks, Word, iMovie, etc. Daughter has been playing the Sims.
Things just open up real quick now. No more beach ball.
I came real close to getting a 1 gig stick. Don't know if we will need much more than a gig for what we do so I went with the matched set to get 128 bit.
I think you will be pleased with what I bought.
Congrats on your new iMac.
Edit:The memory that was shipped to me from Coast to Coast is Princeton memory.
Comments
Originally posted by Powerdoc
I can easily predict what will be your next move. You will replace the 512 MB DIMM by a 1 GB DIMM for a total of 2 GB.
In the PC world there is a huge difference between single and double channel memory bus : expect a 5-10 % speed bump.
Thanks for the very helpful reply.
The developer's note also points out: "The iMac G5 supports CAS latencies of 2, 2.5, 3, 4, and 5."
This all begs the question: what are the exact specs of the Apple memory? If we buy a 512KB machine and then add a 512KB memory stick from a third-party vendor, I assume that we need to match the speed (CL-3 / CL-2.5 / CL-2) in order to get the dual memory bus benefit. Is Apple's RAM prices (and Kingston's) more expensive because it is faster -- and matches Apple's stock RAM?
We may have to wait for first shipments to arrive to sort it out, but for the time being, Crucial offers only CL-3 RAM for the G5 iMac. Kingston's iMac RAM is way more expensive. Given that they the only ones on the ball enough to point out the single / double memory bus issue, might this indicate that Kinston's RAM is more expensive because it is faster.
Of course all this begs another question: if Apple and Kingston's RAM is faster than CL-3, if I put in two 3rd party CL-3 sticks will I experience a performance hit compared to if I used faster memory?
I fully acknowledge that this subject doesn't really make sense in the context of an iMac ("if you are concerned about small incremental speed bumps, dude, you really should just buy a dual PowerMac...").
It's just that given that I am buying an iMac, I'm looking for the price/performance sweet spot...
Originally posted by BK0001
Thanks for the very helpful reply.
Not to add undue complexity, but there are obviously different types of RAM out there for any given size. Crucial offers only CL-3 RAM for the G5 iMac. Kingston's is way more expensive (although they are the only memory vendor on the ball enough to point out the single / double memory bus issue).
Once we set up the computer to have access to a double memory bus instead of single, is there any ADDITIONAL benefit in considering faster (CL-2 or CL2.5) memory?
I fully acknowledge that this question doesn't really make sense in the context of an iMac ("if you are concerned about small incremental speed bumps, dude, you really should just buy a dual PowerMac...").
It's just that given that I am buying an iMac, I'm looking for the price/performance sweet spot...
I don't think that the latency will do a huge difference on Macs. Macs have autodetect feature, and know automatically what kind of Ram latency the DIMM have. If you have one CL3 DIMM, and one CL2 DIMM, the mac, will use the CL3 mode. So if you want the maximum speed, you can choose to go to CL2 DIMM in each slots, but it will be an expansive option and nothing prove that it will gie you a huge benefit.
It's strange that Apple has never really communicate on this point, at the contrary of the PC world where you will find tons of articles about this subject. Perhaps Apple consider that the latency thing do not bring sustantial additional benefit.
Originally posted by BK0001
Thanks for the very helpful reply.
Not to add undue complexity, but there are obviously different types of RAM out there for any given size. Crucial offers only CL-3 RAM for the G5 iMac. Kingston's is way more expensive (although they are the only memory vendor on the ball enough to point out the single / double memory bus issue).
Once we set up the computer to have access to a double memory bus instead of single, is there any ADDITIONAL benefit in considering faster (CL-2 or CL2.5) memory?
I fully acknowledge that this question doesn't really make sense in the context of an iMac ("if you are concerned about small incremental speed bumps, dude, you really should just buy a dual PowerMac...").
It's just that given that I am buying an iMac, I'm looking for the price/performance sweet spot...
No need to buy faster timed memory... not enough of a price/performance bump. Some CL 2.5 isn't much more expensive than CL3, so that might be worth it. It's about a 2% performance bump from 3 -> 2.5, and 2% from 2.5 -> 2.
http://www.extremetech.com/article2/...1637834,00.asp
"While the iMac G5 accepts any combination of DDR400 (PC3200) SDRAM in its two slots, a matched pair will modestly boost performance."
... but again, I guess this is not a PowerMac, and 99.9% of iMac users will never notice or care.
Originally posted by BK0001
Given all this, I just can't believe that Apple doesn't say something like:
"While the iMac G5 accepts any combination of DDR400 (PC3200) SDRAM in its two slots, a matched pair will modestly boost performance."
... but again, I guess this is not a PowerMac, and 99.9% of iMac users will never notice or care.
The funny thing is that the single 1GB costs $525 to upgrade, while the 1GB in pair/dual-channel is only $225
Originally posted by BK0001
Given all this, I just can't believe that Apple doesn't say something like:
"While the iMac G5 accepts any combination of DDR400 (PC3200) SDRAM in its two slots, a matched pair will modestly boost performance."
... but again, I guess this is not a PowerMac, and 99.9% of iMac users will never notice or care.
Actually, Apple did say this today. If you have mismatched pairs, then the bus speed is 64. If the pairs are matched, the bus speed is 128.
So... Here's a question: The iMac comes with 256. If you add another 256, will the performance of the machine be better or worse than if you had added a mismatched 512? In other words, would 512 at 128 be better than 768 at 64 (assuming that you don't ever move into virtual memory with either configuration)?
Originally posted by dws
Actually, Apple did say this today.
Come on!! I did not mean saying it by burying it in a DEVELOPER'S NOTE.
How about on the configuration page, where there is opportunity to mention it either in the explanation or through the "Learn more" link?
Originally posted by dws
Actually, Apple did say this today. If you have mismatched pairs, then the bus speed is 64. If the pairs are matched, the bus speed is 128.
So... Here's a question: The iMac comes with 256. If you add another 256, will the performance of the machine be better or worse than if you had added a mismatched 512? In other words, would 512 at 128 be better than 768 at 64 (assuming that you don't ever move into virtual memory with either configuration)?
I doubt the boost of having syncing pairs of RAM would offset the 256MB of less RAM. I would always go with the higher RAM.
Option 1
Existing: 256
Add: (1) 1 gig stick.
Total: 1.256 gigs
64 bit
$199
Option 2
Remove 256
Add (2) 512 sticks
Total: 1.024 gigs
128 bit
$149
Worth $50?
I lean towards Powerdoc's idea. Option 2. If I am wrong, the next time time I upgrade (if ever) I'll remove a 512 (sell it) and add a 1 gig.
If I buy 1 stick of 1 gig ram and remove the 256 stick that comes with the iMac, will this be at 64 bit or 128 bit. (I'm guessing 64.)
Originally posted by Silas
So identical DIMM means any two PC3200 (400MHz) DDR SDRAM DIMMs of equal size (512+512, etc.), regardless of the vendor?
Its more than just MB size though. the memory timing/latency must be identical for the sticks as well. most quality ram has this onthe sticker on the front and may appear as 2/2/4.5 or some combination of numbers. your best bet is to get two matched pairs to ensure you run in 128bit mode.
Its more than just MB size though. the memory timing/latency must be identical for the sticks as well. most quality ram has this onthe sticker on the front and may appear as 2/2/4.5 or some combination of numbers. your best bet is to get two matched pairs to ensure you run in 128bit mode.
Is the standard apple ram module marked with identifying information (ie "sticker on the front")which will allow us to match the specs? If not, can we get the info from apple? It's obviously not a big deal, but if one can match a memory stick and get 128bit, that seems a worthwhile thing to do. I ordered with a 512k stick and planned to add an aftermarket 512 or 1 Gg. I guess I could sell the 512k that came in the machine and replace with matched sticks. What do you think?
buzz
Originally posted by drbuzz
Is the standard apple ram module marked with identifying information (ie "sticker on the front")which will allow us to match the specs? If not, can we get the info from apple? It's obviously not a big deal, but if one can match a memory stick and get 128bit, that seems a worthwhile thing to do. I ordered with a 512k stick and planned to add an aftermarket 512 or 1 Gg. I guess I could sell the 512k that came in the machine and replace with matched sticks. What do you think?
buzz
Fiscal rule of thumb that bears reiterating: purchase hardware from Apple with the lowest amount of RAM possible for that machine, then purchase additional memory from a third-party, such as Crucial.com, RamJet.com, etc. You'll save some cash. (Incidentally, are you purchasing an iMac? They come stock with 256 MB.)
I can't say for certain, but doesn't the system profiler in OS X provide details such as latency, etc., for the memory?
Incidentally, are you purchasing an iMac? They come stock with 256 MB.)
I ordered a 20" with 512k, thinking I would buy another 512K online somewhere. I'm currently using a peecee so I don't know about OSX system profiler yet.
buzz
Originally posted by LudwigVan
I can't say for certain, but doesn't the system profiler in OS X provide details such as latency, etc., for the memory?
I don't see anything on System Profiler noting RAM latencies. This is on my 12" PB.
Originally posted by MCQ
I don't see anything on System Profiler noting RAM latencies. This is on my 12" PB.
Look at the memory tab and it is under speed. There will be PC<memory speed>-<latency>.
I got it from 18004memory. Coast to Coast. $71.50 per stick. (Bought the PowerMac G5 3200 memory as it was cheaper than the iMac version. Go figure.)
Very easy to install. Took about 5 minutes. (This included time amazed looking at the inside of the beast.)
Things just open up real quick now. No more beach ball.
I came real close to getting a 1 gig stick. Don't know if we will need much more than a gig for what we do so I went with the matched set to get 128 bit.
I think you will be pleased with what I bought.
Congrats on your new iMac.
Edit:The memory that was shipped to me from Coast to Coast is Princeton memory.
Part Number: GPM400X64C3/512/H
Title: 512MB 400Mhz. CL3 184PIN 32X8
Does this sound good?