More RAM doesn't always amount to better performance

[jimbo45]

Hi all
Reading these threads a lot I get the impression that a great many people think that simply by adding more RAM on a computer will automatically improve the performance.

This is not necessarily true as there are many many factors that need to be taken into account.

The amount of REAL RAM allocated by the OS is based on very complex algorithims and not purely on the size of the application being run. For example I might have a HUGE powerpoint presentation (say 50 MB -- a lot for a powerpoint demo) but the actual REAL RAM needed is of the order of a few KB (yes Kilobytes).

Most applications (possibly Photoshop is one of the rare exceptions) do not need to be 100% loaded into RAM while working. Only the amount of real data "pages" need to be accessed at any one time. The amount will obviously dependon what the application is doing , other processes etc etc.

For example in the power point example as above the data has to be transferred to a Video display -- whilst this is being done the next "slice" of data can be read from the "paging" disk.

Applications which wait a lot on input from the User (such as word processing) can use actually a very small amount of RAM since the keyboard input is far far slower than any DISK I/O required to get data from paging into real RAM.

So before you go "buying huge amounts of RAM" think what you actually need.

For a lot of people better graphics, faster CPU and above all FASTER DISKS might make for a snappier system than increasing the amount of RAM once you've got a reasonable base amount installed.

An 8GB RAM system with very slow disks and poor graphics is often far more frustrating to use than a 3GB machine with lightning fast disks and a decent graphic card irrespective of the CPU installed .

I would hazard a bet here that the biggest bottleneck in 99.9% of home systems is not RAM or graphic card but poor DISKS.

Cheers
jimbo

 

[fakeasdf]

This is false... The amount of VMemory allocated to each program is 4 gigs on a 32 bit system. The amount actually in the RAM can be super small yes. Yes the Disk is possibly the biggest bottleneck, but your title makes it seem like more ram can be worse, where in all reality it won't ever hurt. If you have a crappy hard disk, disable your page file, buy 4 gigs of ram and run completely off ram, this will stop page faults (swapping of memory to the hard drive and vice versa) which is a huge performance gainer...

When it comes to games, Graphics cards are your bigger bottleneck, due to the fact that most of your textures etc are loaded into memory. And if you only have a little RAM then your OS is going to be forced to swap memory in and out of the page file, which will really kill you if you have a crappy hard drive, but if you are playing Crysis, more ram and a kick a video card are a way bigger factor than a fast or slow hard drive.

If you aren't a gamer and your machine sucks, get a core 2 duo or better, with a decent hard drive and a ton of RAM

And, it's easier to upgrade ram than say a CPU, also generally more cost effective, but unless you are someone who does some major video editing you probably won't get any performance boost above 2-4 gigs.

 

[baarod]

I think this discussion needs to take into account the application's ratio of locked or non-pageable memory to it's working set. More memory will prevent commit paging of memory marked as pageable even if it is allocated in the virtual heap. The metric you really need to look at is hard page faults, that is, when memory has been allocated as pageable but insufficient physical memory conditions have caused those pages to be committed to the page file and purged from physical memory. A hard page fault occurs when that memory is accessed and has to be reloaded from the page file back into memory. That's where performance is impacted. So, more memory is almost always better!

 

[damoh]

LOL ive just bought 4 gig ram, hope it helps me lol

 

[Mark]

Have to agree with fakeasdf, I started off with a x86 OS and 2 gig of RAM and I could play Crysis but not with very high settings, then I went to x64 and got 4Gig of Ram, every thing else the same and my performance increased dramatically and I was able to play the game on much higher quality setting.

It's strange the way more memory was always better years ago, you have an old computer with 1 Gig and you add another one and WOW look how much quicker everything is, this is great.

That was until x86 reached it limit and that was like hitting the edge of the Worrld for computing and no one wanted to see past it, there is something over the horizon and it's x64 with potential to keep us going for a life time.

Saying we don't need more then 2 Gig of RAM is like saying the World is flat so wake up and smell the coffee.

 

[ollie007]

lol philosophy from an aussie

if you use ramdisk, or just turn off pagefile, then i think you get lots of performance...HDD is the bottleneck in most cases, but SATA2 is bringing highspeed IO to homeusers

 

[whoosh]

LOL ive just bought 4 gig ram, hope it helps me lol

Hey good news M8 sure you will notice the improvement and be able to go 64X = yeah!

Dont wish to (ram) it home but I find the four gig handy do a lot of burning of films and editing etc ... yes a lot of burning indeed recently

 

[smarteyeball]

lol philosophy from an aussie

Is there a problem with that ? :sarc:

 

[fakeasdf]

I think this discussion needs to take into account the application's ratio of locked or non-pageable memory to it's working set. More memory will prevent commit paging of memory marked as pageable even if it is allocated in the virtual heap. The metric you really need to look at is hard page faults, that is, when memory has been allocated as pageable but insufficient physical memory conditions have caused those pages to be committed to the page file and purged from physical memory. A hard page fault occurs when that memory is accessed and has to be reloaded from the page file back into memory. That's where performance is impacted. So, more memory is almost always better!

Yes, this calls for a chart... I tried to update the chart to today's prices, but you'll notice when you hit between ram and hard drive the hit cost is tremendous, it goes from 30 nanoseconds to 8 milliseconds! That is a terrible time loss in the computer world... (for those who don't quite understand that, the cost to hit the hard drive over ram is 266,666 times slower!)

 

[bummpr]

Read this!

Thanks jimbo for another insightful post. Before people start jumping all over jimbo, they might want to read this:

Do You Really Need More Than 6 GB Of RAM? : Is Too Much Really Just Enough? - Review Tom's Hardware

I think his point is there is more to consider in improving your overall performance than laying out hard-earned $$$$ (or euros or yen) for memory which may not be providing the return you think it is.

 

[fakeasdf]

Hah, yes, Toms... That article is all right, but they were showing the differences between 6 and 12 gigs of ram... That's not what most people are at, most people are between 1 - 2, and should go to 3 - 4. But as I said before, if you want better gaming, get a better graphics card If you want to encode faster, get a faster CPU. If you want to run a media server in your house, get a gigabit router/switch and nic. If you want to join a fashion and spend more money on weaker computer buy a mac

 

[whoosh]

I do find the four gig of ram runs things just fine I get a 7.1 base score for my memory everything else is slower 5.6 for the CPU and disk data transfer at 5.9.
Cannot for now buy a faster processor but a future option

 

[black dog]

The Conclusions drawn in the Toms Hardware article appears to say it all, and matches my experience. I recently upgraded to 4 gigs (from 2) and cant say i have noticed any difference in performance. Hopefully i will in the future.

(Excerpt) If 3 GB worked so well, why do we continue to recommend 4 GB to 6 GB triple-channel kits for performance systems? Perhaps we’re just a little too forward-looking, but we can certainly imagine scenarios a typical “power user” could encounter where 3 GB might not be enough, even if today’s tests didn’t reveal any of them

Conclusion - Review Tom's Hardware : Do You Really Need More Than 6 GB Of RAM?

 

[smarteyeball]

The performance difference is subtle in the fact that while there are no 'speed' increases per se (read/write), with 4GB+ you're accessing your pagefile less and less which ultimately 'speeds' everything up.

 

[RST101]

Hah, yes, Toms... That article is all right, but they were showing the differences between 6 and 12 gigs of ram... That's not what most people are at, most people are between 1 - 2, and should go to 3 - 4. But as I said before, if you want better gaming, get a better graphics card If you want to encode faster, get a faster CPU. If you want to run a media server in your house, get a gigabit router/switch and nic. If you want to join a fashion and spend more money on weaker computer buy a mac

Get rep of me for that mate, well said.

 

[Shuko]

6GB doesn't hurt

 

[kpo6969]

4GB ram w/ x86 OS w/512mb gpu never caused me performance loss. In fact it does help. Now a 1GB or 2GB gpu that's a different story.
512mb gpu = 3325mb available system memory (for me anyway)
Plenty for what I need.

 

[fakeasdf]

6GB doesn't hurt

That's why I mocked Tom's article... They didn't use any memory intensive programs while testing. No photoshop, premier, vegas video, avid... You want to do an article on high memory amounts, do something that will use it...

 

[jimbo45]

Hi all

I never meant to say DON'T put more RAM in your machine -- all I
wanted to say is that the way most modern OS'es work (and that includes going back as far as the Venerable MVS/370 mainframe stuff from IBM) adding more memory per se won't necessarily buy you improvement.

My point was essentially to say that you might be better off upgrading Disks and Graphics BEFORE considering any upgrade.

Some applications may well load up totally into Virtual memory before starting - but with superfetch and other OS "tricks" this will only be noticed as a delay on starting the application and then probably not even if you only have 2GB RAM in your machine.

I've seen a 1GB notebook running X-64 build 7068 runnng the 64 bit version of Photoshop quite satisfactorily. -- OK you can't process 1000's of photos in Batch like you can on a machine with more RAM but it's adequate.

Remember in any case instructions have to be moved to the CPU decode area for execution and the CPU's are usually these days multi-processor AND multi-threading. The system will while the instruction is executing have already "selected" and "pre-fetched" the next set of instructions so the delay (especially from fast DISK) will be fairly small.

Large RAM is required for these sets of scenarious.

1) Multiple users concurrently using the Machine (such as Database Servers or even just corporate type servers running corporate applications with multiple users -- basic file and print servers excluded).

2) If you are running a LOT of applications at the same time (and I mean A LOT > 10).

3) You need to "Buffer" HUGE amounts of I/O -- for example backing up quickly several TB of data in the largest chunks possible -- but even here you are limited by the speed that the I/O device can read the data from the Buffers -- whilst one buffer is being read the other can be filled.

4) You need to run a whole slew of Virtual Machines at the same time --one application that does "Eat RAM for Breakfast".

It's NOT wrong to put 8GB of RAM in your machine for example but for typical users you won't actually see much advantage or performance gain -- but you most certainly would by swapping say typical "consumer grade" hard disks for expensive but very fast SCSI Raptors or similar.

Cheers
jimbo

 

[fakeasdf]

I accept your apology... Nah, I'm just messing with you man, that's a much better explanation

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