A Question About Memory and Processing Speed

[Arthur Morris]

In today's Bulletin (www.birdsasart.com/bn297.htm (http://www.birdsasart.com/bn297.htm)) I wrote about the new HP laptop that I just purchased (with a 64-bit operating system is that is the correct terminology).

I wrote: "The more memory you have the faster your processing speeds will be."

If my own memory serves me well, I have been hearing for more than half a decade that the more memory you have, the faster Photoshop will run. "4gbs of RAM is great, but 8gb would be better.

I got this via e-mail today:

"I don't know where you got that bit of misinformation, but it is totally wrong. Memory is merely a place to store things and has absolutely nothing to do with processing speed. Anything over 4 gigs is a waste of space for 99.999% of computer users."

Does anyone know if this guy is correct? I don't mind being wrong once in a while; I would simply like to learn truth.

[Nick Palmieri]

Art I am not a computer expert but will share my understanding. 64- bit means that the processor can process more chunks of information at one time, this will make the computer faster. Rather than sending smaller bits of commands at one time (8 or whatever) it can send 64 making every process on the computer faster. I don't believe RAM memory (your 4gbs) has anything to do with this directly (other than it can send larger chunks from the hard drive to the RAM). Data is stored on the hard drive when you start working with it, it loads the info to the RAM memory for fast access). Of course more memory the better/faster becasue it is easier accesssed. Of course it depends on the programs you are using and the size of the files etc. If you are using CS4 and have 5 RAW files open, and MS Word and Outlook open, and you are listening to iTunes, you better believe you want as much memory as possible. I have a Media Room computer that has 16gbs. of memory, so I can watch bit for bit Blu-Rays. When I was just watching DVD's ,4 megs of memory worked just fine.

So technically the more memory will make your computer run faster because it can access the data quicker, but the more bits you have the faster your prcessor will work. Therefore everything will work faster. My opinion is that photographers using PS are in the <1% anyway, so its needed.

I am not a computer guy but that is my understanding, hope this helps or confrms your stance. I am sure someother computer experts will add there opinions.

[Bill Coatney]

http://en.wikipedia.org/wiki/Random-access_memory

I guess he was insistent on being specific and precise in speech(yes, there is a "difference") but more RAM will speed processing so you were not telling a fib and was just as precise as needed.

As far as "memory" and processing,Photoshop also asks you to designate a scratch disk which is much slower than RAM.

enjoy your new machine

[arash_hazeghi]

Hi Arti,
The comments sent to you are harsh and somewhat rude, I don't think the guy deserves a reply. It is true that amount of memory does not directly affect "processing speed" as that is determined by the CPU, however faster memory (ex DDR3 vs DDR2, triple channel vs dual channel) means quicker access to data for CPU and thus faster running of applications. In absence of sufficient RAM, operating system (Windows, Mac OS etc.) allocates scratch space on hard disk (which is two orders of magnitude slower than RAM) which makes things a lot slower, because every time data has to be read from HDD, transfered to RAM and then sent over the CPU and vice versa, so in practice more RAM does make programs like PhotoShop run faster, but if you have sufficient memory that everything fits in, adding more will not make things faster. 4GB is generally good, but if you run certain software it may not be enough, I have 12GB of RAM on my Windows machine.

Best,
AH

[LouBuonomo]

Well he is right in a way.. When you talk about the speed of a processor, system memory has nothing to do with increasing speed. Processor cache is a story for another day.

But you should not care about just the processor speed, the thing you really care about is how long it takes the system (processor, memory, I/O and display) to complete a task.

PS is a system memory hog and the more you give it the better. We could go into a long discussion how programs load into memory and swap in and out by the OS as needed but I think you get the idea. Yes he is right that memory is a place to store things but he is confusing disk memory and system core memory. Programs are moved in out out of system memory as needed in a multitasking OS like windows and Mac-OS.

A 64bit system allows the OS to address more memory therefore allowing more programs (or bigger programs) to fit without having to swap them in and out to disk which is time consuming.

The config you purcased should serve you well..

Make sense ?
Lou

[William Malacarne]

Arti

You need a 64 bit operating system also. ...most windows are 32 bit unless you order a 64 bit and you will also need photoshop and others software to be 64 bit, again the normal will be 32 bit. Lightroom 2 comes to you as a 32 and 64 bit. All plug-ins for photoshop are not ready yet for 64 bit but I think many of them are.

Bill

[LouBuonomo]

Well he is right in a way.. When you talk about the speed of a processor, system memory has nothing to do with increasing speed. Processor cache is a story for another day.

But you should not care about just the processor speed, the thing you really care about is how long it takes the system (processor, memory, I/O and display) to complete a task.

PS is a system memory hog and the more you give it the better. We could go into a long discussion how programs load into memory and swap in and out by the OS as needed but I think you get the idea. Yes he is right that memory is a place to store things but he is confusing disk memory and system core memory. Programs are moved in out out of system memory as needed in a multitasking OS like windows and Mac-OS.

A 64bit system allows the OS to address more memory therefore allowing more programs (or bigger programs) to fit without having to swap them in and out to disk which is time consuming.

The config you purcased should serve you well..

Make sense ?
Lou
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[James Shadle]

"I don't know where you got that bit of misinformation, but it is totally wrong. Memory is merely a place to store things and has absolutely nothing to do with processing speed. Anything over 4 gigs is a waste of space for 99.999% of computer users."

Only true for the 99.999% (seems really high) who use a 32 bit operating system.
32 bit systems can only utilize a little over 3 GB of RAM.

Those of us who use 64 bit operating systems will see a performance improvement with additional RAM.

"The more memory you have the faster your processing speeds will be."
True, with 64 bit systems. You said processing speeds, not processor speeds.

The processor speed will not change, however the processing speed will.
Using less Virtual memory is one example of how processing speeds will improve.

When RAM runs low, Windows uses Virtual Memory. Virtual Memory is just data stored on a hard drive when Windows runs low on RAM. RAM transfers data much faster than a hard drive.
So the more memory you have the less often you will need to use the slower Virtual Memory.

An absolute improvement in "processing speed".

James

[Axel Hildebrandt]

"I don't know where you got that bit of misinformation, but it is totally wrong. Memory is merely a place to store things and has absolutely nothing to do with processing speed. Anything over 4 gigs is a waste of space for 99.999% of computer users."

Only true for the 99.999% (seems really high) who use a 32 bit operating system.
32 bit systems can only utilize a little over 3 GB of RAM.

Those of us who use 64 bit operating systems will see a performance improvement with additional RAM.

"The more memory you have the faster your processing speeds will be."
True, with 64 bit systems. You said processing speeds, not processor speeds.

The processor speed will not change, however the processing speed will.
Using less Virtual memory is one example of how processing speeds will improve.

When RAM runs low, Windows uses Virtual Memory. Virtual Memory is just data stored on a hard drive when Windows runs low on RAM. RAM transfers data much faster than a hard drive.
So the more memory you have the less often you will need to use the slower Virtual Memory.

An absolute improvement in "processing speed".

James

That's my understanding, too. If OS and PS are both 64bit versions, more RAM should improve memory-intensive tasks in PS.

[Arthur Morris]

Thanks all above. Lou, as James pointed out I referred to processing speed, the speed at which Photoshop does what we want it to, not the speed of the processor. In addition, I traditionally have too, too many windows open while Photoshop is running...

[Arthur Morris]

Again, I said faster processing speed (not processor speed), the former referring to the speed at which Photoshop can perform various tasks.

Yes, the guy was being quite rude but I am a lover of what is, therefore.....

Peter: I am using CS-3. And as you know, I am a computer dummy. Is this statement correct?: "

Since I am using Photoshop CS-3 I would get the exact same performance from my computer with 4gbs of RAM as I would with 8 gbs of RAM."

Pick one: yes or no <smile>

[John Chardine]

Unfortunately, the answer is not black or white Artie. If the file you are working on in Photoshop is pretty small, say a 10 mp image from the 1DmkIII, you will not likely see a difference in performance between 4 and 8 gb of memory. The reason is that the file can fit into available memory without having to resort to being "paged out" to your hard disk. If the file was large- say a 5D mkII image that you have upsized, then you would likely see a difference in performance. As Peter and Arash suggest, paging out to the hard disk is the kiss of death for performance so you want to avoid this at all costs.

One way to reduce the chances of paging out is to adjust the amount of memory Photoshop will use. Go to Preferences-Performance and adjust the "Let Photoshop use" slider to use more memory.

As a general rule the more memory you have the better so if you can afford 8gb, then "fill your boots" as they say.

[LouBuonomo]

Then if you like a lot of windows open you will see better overall performance.

[John Chardine]

I thought I was going mad- I had just replied to this thread and saw lots of other replies, but none of them are here. Turns out the same thread is in General Photography forum! OK I'm not going mad.

[LouBuonomo]

If you keep a lot of windows open you will see better performance... Vista has a lot of crap going on in the BG so the more mem the better...

[Arthur Morris]

This just in from Scott Bourne who is a very smart man:

Since several programs cache the files in RAM as you work on them you are absolutely correct and he is absolutely incorrect.

I really like simple and I do not mind being told that I am right....

[Arthur Morris]

Unfortunately, the answer is not black or white Artie. If the file you are working on in Photoshop is pretty small, say a 10 mp image from the 1DmkIII, you will not likely see a difference in performance between 4 and 8 gb of memory. The reason is that the file can fit into available memory without having to resort to being "paged out" to your hard disk. If the file was large- say a 5D mkII image that you have upsized, then you would likely see a difference in performance. As Peter and Arash suggest, paging out to the hard disk is the kiss of death for performance so you want to avoid this at all costs.

One way to reduce the chances of paging out is to adjust the amount of memory Photoshop will use. Go to Preferences-Performance and adjust the "Let Photoshop use" slider to use more memory.

As a general rule the more memory you have the better so if you can afford 8gb, then "fill your boots" as they say.

Hi John, Remember. I am a computer dummy so let's get really basic: what is paging out to the HD? How do you know when it happens? How does death kiss you in this case???

Thanks for the cool diagram and the effort you put into replying. But as a curious dummy I will be calling upon your help and Peter Kes's until I can pretty much understand the whole thing in simple language. Then at least I will have my new machine set up properly.

BTW, I posed this same question in the Digital Workflow Forum and it is getting lots of play there also.

[Arthur Morris]

Sorry about that John. I did not expect so many answers so quickly so I posted the same question in the two Forums. Thanks for your excellent post to the one in General Photography.

[Grace Scalzo]

All I know is that I have basically the same laptop as you do, and with 4 gigs of ram it ran slowly, with 8 it's noticeably better.

[Peter Hawrylyshyn]

Artie -
Your new laptop will run under Vista ( 64 bit) system
It's my understanding that CS3 is not have a true 64bit OS application
http://blogs.adobe.com/scottbyer/2006/12/64_bitswhen.html
This was only introduced in CS4

So although CS3 may run on your 64-bit Vista laptop - it won't take full advantage of the 64-bit OS and expanded memory opportunities. For that you'll have to upgrade to CS4

[John Chardine]

OK Artie, so "paging out" is part of the management of Virtual Memory. Operating systems (OSs) use Virtual Memory and so does Photoshop independently. Virtual memory uses your hard disk as a temporary storage place for portions of physical memory and makes your machine seem like it has a lot more memory than it really has. What happens is that if a program and files call for more physical memory (your 4 or 8 gb) than you have, the OS or Photoshop will temporarily record a portion of that memory on your hard disk, freeing up that physical memory for use. Then later on, the hard disk may need to be read to retrieve that portion of memory that was written there. This recording to and reading from hard disk = "paging out and in" is MUCH slower than accessing physical memory so paging in and out slows your machine down. A symptom of paging in and out is as follows- you ask Photoshop to do something and suddenly the hard disk starts to be very active, and you watch the screen as something that should have taken a second takes 15, 20, 30 seconds to complete (the kiss of death).

[Arthur Morris]

Thanks John and Peter.

I think that I am understanding the paging out stuff <smile>

Peter, when I do get the new machine, we need to talk about the mirrored HD bit.

[Mark Fuge]

Thanks for asking the question Artie.

I am ordering my new computer tomorrow, after a few weeks of research and had similar questions that were very well answered here. Like you, I am glad to find out that I was right! ;) :D But I am glad to have others with more Geek experience than me, anything exceeds 0.01, confirm it.

Good luck with your new puter. Now you have to update your PS. I have it already, so I won't sweat that part of the purchase.

[Peter Hawrylyshyn]

Artie -
you may find this link (how to optimize CS4 on Vista) useful:
http://kb2.adobe.com/cps/404/kb404439.html

It states:
The primary advantage of using the 64-bit version is to access amounts of RAM beyond what Photoshop can access when the 32-bit version is run. You can take advantage of more than 4 GB of RAM only when you are on 64-bit Windows, using 64-bit Photoshop. If you use files large enough to need more than 4 GB of RAM, and you have enough RAM, all the processing you perform on your large images can be done in RAM, instead of swapping out to the hard disk.
This table lists the amount of RAM available to Photoshop with the different versions of Windows:
<table xmlns="" class="data-bordered" width="100%"><tbody><tr><td class="cellrowborder" valign="top"> Photoshop Version </td> <td class="cellrowborder" valign="top"> Windows Version </td> <td class="cellrowborder" valign="top"> Manximum amount of RAM that Photoshop can use </td> </tr> <tr><td class="cellrowborder" valign="top"> 32-bit </td> <td class="cellrowborder" valign="top"> 32-bit </td> <td class="cellrowborder" valign="top"> 1.7 GB </td> </tr> <tr><td class="cellrowborder" valign="top"> 32-bit </td> <td class="cellrowborder" valign="top"> 64-bit </td> <td class="cellrowborder" valign="top"> 3.2 GB </td> </tr> <tr><td class="cellrowborder" valign="top"> 64-bit </td> <td class="cellrowborder" valign="top"> 64-bit </td> <td class="cellrowborder" valign="top"> as much RAM as you can fit into your computer. </td></tr></tbody></table>

[Arthur Morris]

Peter, I am sure that I would find it useful if I had CS-4. Maybe I will break down one day and get it but from what I have seen it most pretty much the same as CS-3 in a more confusing package that is more difficult to use and less intuitive than CS-3.

[Arthur Morris]

Well he's partly right: if your workspace doesn't fit in memory, you will be killed by paging. It is a matter of being able to use this memory for your main application, Photoshop. Are you using the 64-bit version yet and how much can it address ? I think PS CS3 is still 32-bits and my version could only use (See PS preferences -> Performance) 2.2GB. The rest is than for use by other applications.

H i Peter, I am still struggling to understand this.

1-Let's assume that I stick with CS-3. I am using CS-3 but have several other programs open. These would usually include Breezebrowser and six or seven BPN windows. Would there be times when having 8 gbs of RAM rather than 4 would allow either Photoshop or the other programs to run faster and/or more efficiently?

2- I do not at all understand part of this statement: "If your workspace doesn't fit in memory, you will be killed by paging."

What does "If your workspace doesn't fit in memory" mean?

And please try explaining "paging" or "paging" out to me in simple terms....

Above, John Chardine wrote, "if a program and files call for more physical memory (your 4 or 8 gb) than you have, the OS or Photoshop will temporarily record a portion of that memory on your hard disk, freeing up that physical memory for use. Then later on, the hard disk may need to be read to retrieve that portion of memory that was written there. This recording to and reading from hard disk = "paging out and in" is MUCH slower than accessing physical memory so paging in and out slows your machine down."

Is this correct: sometimes a program like Photoshop needs more than the 4 or 8 gb of RAM that you have so it puts some of the data on the HD. Then when you need that data, it takes a long time to access it. Am I correct in understanding that this is "paging out"? When you open a Levels dialogue box or save an image and it takes 30 seconds instead of 1-3 seconds is the system paging out?

Furthermore, it would seem that--in the scenario above--if you had more memory, say 8gbs instead of 4gb, that the system would be less likely to page out. Is this statment true of false.

Thanks for your continuted help.

[LouBuonomo]

You basically got it... but don't get crazy about it paging, it is a fact of life and most of the time you don't even notice happening. That is why things like hi RPM disks and SSDs exist to minimize the latancy of the read/writes.

Basic rule since the 70s, if it's slow.... add more memory :)

[William Malacarne]

Arthur

Do you have two internal Hard Drives? When you page out that is going to where ever you put your scratch disk. If scratch is on the same disk as your Operating System it can also slow you down. When multi tasking you will be reading and writing at the same time in some cases. So if you are trying to do both to the same disk at the same time on the same disk it can not do it. With two disks it can.

Bill

[Arthur Morris]

I have two HDs and will have two on the new machine. And I always put the scratch disk on the secondary drive.

[Jamie Strickland]

for CS3 yeah if the only thing your running is that on a 4GB vs 8GB machine you probably wont see much difference

now try having LR open, a bunch of other things and then you will see a difference for sure

I upgraded my vista 64bit from 4 to 8GB of ram and I am pretty sure there was a small performance gain within LR itself, but then when I started using the Nik plugins and also PS at the same time I noticed it was running smoother for sure.

I have not upgraded to CS4 yet but I suspect you would see a bigger impact with it vs cs3 for sure