RAM theories

[Steve Grisetti]

The rule of thumb has always been the more RAM the better. But then I read an interesting article about Windows and RAM in a column on Vista published by ZDNet.

According to the author (who's does all kinds of wild experiments on computers) it's nearly impossible to use a full 2 gig of RAM, unless you're running some kind of virtual environment. And, beyond 3 gig, Windows doesn't even know what to do with it. (Except for 64-bit operating systems, which are a whole other issue.)

We've seen a lot of postings on the forums from people who had huge RAM loads -- and it even seems, from what I've seen, that anything over 2 gig is prone to problems. (In my experience, the sweet spot for Premiere Elements is at least 1 gig but no more than 1.5 -- but I've not tested that on Vista.)

Anybody out there have any real life experience to confirm or repudiate that?

As we enter the age of dual and even quad core processors and multiple gigs of RAM, it might be nice to know if there is such as thing as too much power for the operating system to handle (leaving intensive programs, such as Premiere Elements, the unfortunate victim).

[ed]

Where I work we don't go over 2 gig for ram for the reasons you've said, there is no gain with the development tools we use.

[Chuck Engels]

I have 2.5GB of RAM running Windows XP Home. I have not seen a time where the machine has used all of my RAM. I do not have any problems running any programs however so maybe the sweet spot is a little higher for some people.

[Bob]

...beyond 3 gig, Windows doesn't even know what to do with it.)

Not quite.

It's common to confuse physical RAM with Virtual Memory. The Operating system has full and complete access to all the physical RAM installed and will utilize all of it if need be. The OS has no problem with large amounts of physical RAM. A 32bit OS can address 4GB in each system address space. If you have more than 4GB RAM installed the OS will use it as an in-memory cache. The 3GB limitation for applications applies not to physical memory but to virtual memory. Virtual memory is mapped memory which appears to the application as if it were physical memory but only the portion currently being used resides in physical memory at any given moment in time. The 1GB of virtual memory not available to the application is being used by the Operating System to map to system routines, tables, and common memory areas.

The author was also talking about business applications. Those typically aren't all that resource intensive. Furthermore, using multiple instances of the application doesn't mean that you are duplicating all the application memory requirements. Because much of the code is reentrant, you're really only loading the unique data associated with the particular instance. So, feel free to add those tabbed pages in the browser. Also, those background processes are probably swapped out unless they are actually doing something and are not idle. Under these circumstances, it is very true that you can easily get by with less physical memory.

The situation changes significantly when you have applications that require significant paged in memory. Virtualization is one example. But, you can also see it in database applications and memory intensive applications such as Photoshop. Premiere Elements doesn't appear to be all that memory intensive -- it appears to be more cpu bound and affected more by memory bandwidth. It does large amounts of calculations on small amounts of data at a time and the data is transferred frequently. This results in the paradoxical situation where the cpu is difficult to drive to high utilization despite the potentially high cpu requirements because of the memory channel bandwidth limitations.

[Clayton]

I wish I was smart enough to understand what Bob said.
Maybe someday I will have a grasp on memory and virtual memory.

[Steve Grisetti]

Bob, do you have a recommendation for the "sweet spot" RAM load for Premiere Elements? Is it different for Vista?

I still say, with XP, 1 gig is ideal. I've tweaked my registry to minimize paging and keep most of my active programs in RAM, but I still rarely exceed that load and my program(s) function perfectly -- even if I'm editing video while also editing in Photoshop Elements, running an e-mail program, browzing the internet and sometimes even test-driving music with a media player.

In short, is more ALWAYS better, or is there a point where you get diminished returns and/or even malfunction?

[hpharley90]

Clay I'm glad I'm not the only one confused.
After reading all of Bob's post I said to myself.

What did he say? :

Some day I'll understand, I hope.

[Chuck Engels]

I've been looking at Dell Precision machines at the Outlet, some of them have 64GB of RAM What would you do with that?????

[hpharley90]

64GB!!

As Phil Rizutto would say "Holy Cow".

[Ken Jarstad]

As I said in another topic yesterday, the one regret I had was buying bargain RAM. At the time I thought the performance gain was not worth the extra money. In the two years since then I have looked at numerous published benchmarks for video apps and have come to the conclusion that Bob presented. After getting the most CPU power you can afford the next bottleneck for video editing performance appears to be memory bamdwidth. I now recommend buying RAM to maximize the bandwidth capabilities of your motherboard. In fact, rather than trying to get ahead of the game with four processors, I would recommend getting 2 GB of the fastest RAM available. I think an extra $200 spent there would have saved me a fair amount of rendering time in the last two years!

[Clayton]

In the latest issue of Maximum PC they built a "Dream Machine". In it they used 2gb Corsair Dominator 1000 @ $610.00. Their total for the machine was $11,595.00 Anyone interested?

[hpharley90]

I would recommend getting 2 GB of the fastest RAM available. I think an extra $200 spent there would have saved me a fair amount of rendering time in the last two

What is the fastest RAM?

Is it the 533MHz and 667MHz numbers?

If those numbers determine speed and 667 being the faster can 533 sticks be replaced by 667?

[Chris B]

Odd how the same kind of article pops up in different places. This one
http://www.anandtech.com/gadgets/showdoc.aspx?i=3034
talks about games and memory limits. It is technical but goes into the detail of memory management and allocation. I wonder about some of the PE crashes with high memory usage being caused by virtual size exceeds 2GB.

[Chris B]

What is the fastest RAM?

Is it the 533MHz and 667MHz numbers?

If those numbers determine speed and 667 being the faster can 533 sticks be replaced by 667?

This is (as with many things computer related) complicated. Generally - yes - but you motherboard has to support it. I'll see if I can find an easy to understand link.

[Bob]

Sorry, I'll try to remember to speak English next time. As Chris says, these computer related things are complicated!

What is the fastest RAM?

Is it the 533MHz and 667MHz numbers?

If those numbers determine speed and 667 being the faster can 533 sticks be replaced by 667?

The quick answer is yes, it's those numbers, and yes, you can replace a 533 stick with a 667 stick. Just don't expect it to run at that speed.

Without getting into a lot of detail, and perhaps even over simplifying things a tad, those numbers represent the data transfers per second that the memory module is rated to perform. The higher the number, the faster the memory. Memory modules are driven by the memory controller on the motherboard. You cannot go faster than what the motherboard can perform. But, memory modules can be run at slower rates with no problems.

FYI, the other designation you will see for memory modules, PC2-4200 for example, is the nominal theoretical bandwidth of the module. DDR2 memory transfers data on a 64 bit channel (8 bytes), so the bandwidth is 8 times the data transfer rate. 533 times 8 equals 4264, the peak data bandwidth, which when rounded becomes 4200.

Then there is Dual Channel. Dual channel memory is a motherboard capability, not a memory module capability. With dual channel, the memory controller can utilize a second 64 bit channel so the effective memory bandwidth is doubled. The memory modules must be matched to run in dual channel mode (the modules must have the same type and number of memory chips on each stick). Memory manufacturers sell dual channel memory in kits with two matched sticks.

If you have more than one speed memory module in your system, the slowest one is the one that rules.