RAM memory

[FredG]

Although I've used PC's for over 25 years, I'm still not as well versed as I sould be. I'm looking at upgrading and have 2 questions:

1. According to the "more is better" mantra, 4GB of RAM appears attractive. I read on a computer forum that the OS can access the entire 4GB, but Photoshop, etc may be limited to use less than the total available. (Implied that more than 3GB is a waste) Can someone please help me sort out truth from fiction? I also read and understand that a graphics card with its own RAM is desirable.

2. I'm confused over "Intel Pentium D with dual core technology" and "Intel Core 2 Duo Processors" I think all I need is a 30,000' overview. This computer will be dedicated almost exclusively to photo processing with PS and perhaps lightroom, other photo related programs, and occasional light duty video processing. The old computer will be used for everything else.

Thanks!

[Stourmi]

Actually if you want something geared just towards photo processing, you might want to look into Apple's Macintoshs. They have a very stable OS, and are built like a MAC Truck. I know a lot of the big companies that do video/photo processing use Apples. I think that their version of Photoshop is called Gimp, and I think it is a free download as well.

As far as the PC. 3gb of RAM should be plenty for what you are doing, and while a high end video card with its own built in RAM is good - you may get better results with a lower end video card, and just allocating more of your system memory to it. Besides you can have all the RAM in the world, but if you don't have a good motherboard, processor, and hard drive - it won't make that much of a difference.

As far as the processors. I would go with the Intel Pentium D with dual core technology processor. The reason I say this is because it had the capability to do the work of two processors at once. Its like having a motherboard that has two processors on it instead of just the one....hence more speed.

Now that being said. You will definately want to look at a hard drive that has more speed to it than your normal run of the mill hard drive because no matter how much speed you have in the processor, and RAM...it won't matter much if you don't have a hard drive that can keep up with it. The higher RPM that you get the faster the hard drive, and the faster your computer will work as a whole.

Also, you are going to want more than just the standard amount of fans. That much speed is going to create a LOT of heat, and you don't want to have overheating issues which can cause shut down issues. If the case the computer comes in has the option of adding more case fans then it is a good idea to go ahead and do it to prevent future issues. Also with having several fans, you are also going to want to keep them clean. Probably about once a month you are going to want to take a can of compressed air, and open the computer up to blow out all the dust, and if you have animals - the dander.

I hope this helps, and that I explained it well. Sorry about it being so long. I have been a computer technician since '96.

[jflint]

Fred,

Dual Core is like having two processors on the same board, (i.e using the same RAM). This may be helpful if you often run two programs at once that both are processor intensive. My limited understanding is that many programs currently available cannot take advantage of a dual-core processor, but PS can.

As far as RAM, I'm not sure that someone (even for photo processing) would really need 4GB of RAM. I could see this much for video, but not for stills. Others may have more enlightened opinions.

Jason

[nhfirefighter13]

The dual core/ core 2 processors are awesome. I have a new Dell pc with with a Core 2 Duo 2.8gig with 2gigDDR memory and the thing is a rocketship compared to what I had before.

From what I understand the dual processors really shine when you are doing multiple things at once...say like having photoshop and your favorite video editor open at the same time.

I'm sure one of the computer gurus here can offer up a better explanation.

[MatsP]

1. All operating systems have a "kernel / user mode" split, which is that some address is considered "kernel mode" (i.e. belongs to the ACTUAL OPERATING SYSTEM, as opposed to an application running on top of the OS).

Windows XP (not 64-bit edition) has a maximum addressable range of 4GB in total, and the normal split is 2GB for user-mode (applications) and 2GB for the kernel (OS itself). This can, with some restrictions be changed to 3GB user/1GB kernel, but some functionality may be restricted in the OS.

However, if you run two different applications (including two copies of the same app, such as two Photoshop's), you can use up to 2GB in each of those - at least in theory, as if you have 4GB of total memory, the kernel will absolutely use up some of that, the rest is available to be shared by everything running on the machine, including in this example the two photoshop copies. Windows XP is capable of "using" 4GB of RAM (see http://www.support.microsoft.com/kb/555223). Other versions of Windows can use more.

Of course, the 64-bit version of Windows XP is capable of using more than 32-bits to address memory, and the limit for physical memory is what the motherboard can cope with (today, up to 32GB depending on motherboard, more commonly 8-16GB). And each application could in theory get an address space of 256TB minus a few gigabyte for the OS kernel and other "admin stuff" (1TB = 1024GB, 256TB = 262144 GB).

Another brief note: If you buy 4GB of RAM, you'll not be able to use ALL OF IT - some space in the first 4GB will be taken up by your graphics card (say 256MB) and other components that are "PCI devices" (even if they are not actually in a PCI/PCI-Express slot). This means that anything from 256 to 512MB of memory will be "hidden" by the devices - and they need to be in the first 4GB because that is what the processor can address in 32-bit mode.

2. [Personal opinion]AMD makes really great processors. Intel isn't bad either, but not quite as good![/personal opinion]. (I work for AMD ;-) )

Intel Pentium D dual core technology is essentially two Pentium 4 "Prescott" that has been fitted together in the same package - but they are to all intents and purposes (except for the number of sockets they use) TWO processors, of a fairly old age now.

The Core 2 processor is a new generation processor based on the Pentium M (which in turn is a souped up Pentium 3 processor). These are lower frequency, lower power, higher performance and a real pain in the butt if you're an AMD Salesman... ;-) The "Duo" version is a dual-core version which is ONE processor with two cores - so it's a "proper" dual core processor, rather than the dual core of the Pentium D which is just a packaging of two processors in one packet.

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Mats

[MatsP]

As far as the PC. 3gb of RAM should be plenty for what you are doing, and while a high end video card with its own built in RAM is good - you may get better results with a lower end video card, and just allocating more of your system memory to it. Besides you can have all the RAM in the world, but if you don't have a good motherboard, processor, and hard drive - it won't make that much of a difference.


Ehm - as a former graphics driver developer, I take offense to that. I agree that low-end graphics cards are "plenty good enough" for Photoshop work (and almost anything else) - but using system memory instead of graphics memory is not a valid point! If your graphics card hasn't got enough onboard memory, it will run dog-slow, because it's not getting the data out of the host memory (i.e. the "CPU memory") fast enough - the graphics memory on todays graphics processors is running at something like 4x the speed of the CPU memory on a modern machine [example, the 3DLabs P20 has a 512 bit wide bus, running at 800+MHz (400+ and DDR), whilst a top-end standard machine (not an overclockers special) would run 800MHz over a 128 bit bus. And of course, going over a AGP/PCIe bus to get the data will just add delay to the memory access].

I may not have worked as a computer technician (ever), but I do have a fair knowledge about how computers work in many aspects.

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Mats

[Stourmi]

:) That is why I said "may". It may or may not help you depending on your budget, and the system configuration you have. Built in Video cards, and some of the lower end cards use your system memory, and if you want similar results without the cost a simple re-allocation of more memory to the video card will speed it up. Also if he gets 3-4gb of RAM he will have more than enough to allocate to it.

You can do the same if you have a video card with it's own built in memory too, to get it to run faster as well.

There was no offense meant, and as we all know there are several different ways to do the same thing on a computer.

[MatsP]

Ok, builtin graphics cards use the same memory controller as the processor, so it's sharing the memory access. A good way to reduce the processor performance if you're using high res. on your PC... [Displaying 1600 x 1200 @ 75Hz, 32bpp takes 1600 x 1200 x 4 bytes -> 7.6MB, 75 times a second -> 576MB/s. That'as about a quarter of what your memory can sustainably deliver... Of course, it's significantly less if you run lower resolution or very slow refresh rate]. This is obviously on top of the any memory required for the graphics card to produce the image that it's drawing to the screen...

Sorry, but I'm not a fan of built-in graphics - possibly because I'm a fan of high resolutions. Although, admittedly, it makes the machine less expensive than having a card stuck in a slot.

More memory in the system is almost ALWAYS a good idea. Two of my desktop machines have 2GB, my laptop has 2GB, another of my machines has 6GB, and the others have 1 and 1.5GB... My home machine that I don't use much has 512MB.

And most low-end graphics card definitely have enough memory to do trivial 2D graphics, such as photoshop. More memory on the graphics card is only really usefull for 3D graphics with textures, vertexlists and 3D drawing "programming" (such as pixel or vertex shader programs). But if you DO need the graphics card to do that, and you don't have enough graphics memory as per what the application requires, then you're going to end up with something REALLY SLOW.

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Mats

[FredG]

Thank you one and all for the most helpful education you provided. Now armed with a little knowledge, I can be really dangerous. Anyone else want to make a contribution to my education?

[agesilaus]

I'd like to point out that the Core Duo is said to be substantially faster and run much cooler than older models. Your computer has many processes running in the background, windows services, antivirus, firewall and so on. Spliting these apps up between 2 processors speeds up the system considerably and lets foreground apps like PS run much faster from the reports I've seen

[FredG]

Good point. I had focused on just the main apps I would run, forgetting how amazed I am every time I look at how many things are running in the background.

Just thought of another question: I have always seen RAM identified as the champion of image processing speed. How important is a few extra 10ths of a GHz on the processor? It seems like that last step to go from 2nd fastest to fastest gets more pricey than earlier steps.

[MatsP]

RAM speed and size will be very important, compared to the processor speed.

Processor pricing is based on "the fastest is always attractive", so going one or two speed-grades down will not loose you much performance, but give you quite a few dollars extra to spend on more memory or bigger screen - which will probably do more fore you. Bigger cache in the processor will also help to some extent - so if there's one model that is slightly slower clock-speed, but has larger cache than some other model, I'd recommend the one with the bigger cache before the faster one.

Remember also that Photoshop doesn't work on the compressed version of the picture, but every pixel is 4 bytes, so a 12MP image will take up 48MB - most processors have one or two megabytes of cache, so not really getting much out of the cache [but it would be MUCH slower if you turned off the cache].

--
Mats

[FredG]

Thanks again!

[jliechty]

The practical reality of using 4GB of RAM in a non-x64 system is that, as MatsP pointed out, some RAM is "eaten" by various devices. XP Pro (32 bit) "supports" 4GB of RAM, but you'll (almost) never be able to get more than 3GB of usable RAM. Note that in this case I refer to physical RAM, as opposed to virtual RAM (what MatsP was saying when he mentioned the 2/3GB per application limit, though he also discussed physical RAM).

To use more than 3GB of RAM, you have to install XP x64. It works fine - I've been using it for almost a year - but driver support is still spotty. Gretag Macbeth color management devices are supported, but I've not heard anything on ColorVision or others yet. Printer support has improved over the past year; Epson has drivers for most of their popular models, and Canon seems to have gotten the memo (and done something about it) to a greater extent than they had when I checked a year ago. Scanners are in a much sorrier state than printers, unfortunately, and tethered shooting of DSLRs is a nightmare (read: impossible). In other news, XP x64 is incompatible with ancient programs that have 16 bit code in them (sadly, that didn't die with Windows 3.1).

On processors: I use an AMD Athlon 64 X2 system, which is great (much better than the Pentium D's in their day). Intel's Core 2 Duo is worlds better than the Pentium D, and also has advantages over the X2's. Either get an Athlon X2 or a Core 2 Duo, but stay away from P4-D at all costs (including the A/C bill during the summer from having a power-hungry space heater under your desk)!

[FredG]

Well, that sure explains why the P4-D cost was so much below the Core 2 Duo cost. They were almost giving it away.

Also sounds like I should stay with X32. The trade-offs to have the X64 don't seem justified in my personal situation.

I feel so much more enlightened than I did this morning. Thanks again, everyone.