LR3.6 running slow if...

I'm posting this here, because I think it's the computer more than Lightroom.

I have a computer that was given to me a while back, when the original owner upgraded to something else. He had the computer built for him and when it stopped working, he upgraded. I found the problem to be the video card and replaced it and have been using it ever since.

LR runs fine and fast, as long as I'm doing no real processing. However, if I start getting into skin and hair masking and whatnot, it starts to bog down. Opening the task manager will reveal that only about 45% of ram is in use, but LR is using 100% of the processor. This happens, also, when simply bringing a photo up that has had skin and hair masking/processing. When I say it slows down, I mean it will be minutes before a change is seen, when moving the sliders. Or, if opening LR, and that image was the last image displayed (so it is what comes up when you open it), LR will open quickly, show the image in the library, and show the "loading" message for quite a few minutes before I am able to do anything.

LR 3.6 is installed to C:. My catalog is installed to D:. The Camera Raw Cache is set for 50GB is located on D:. I have tried it on C:, as well, with no change.

The Windows paging file has been tried on C: and D:, both system managed size, with no change.

Just for giggles, I went into the nvidia control panel and made sure that the GTS 450 was set to be used by LR (I think LR is a CUDA compatible application? It didn't say it wasn't.)

MSI Motherboard MS-7390 (K9N SLI-F V.1)
AMD Athlon 64 X2 Dual Core 6000+ 3.01 GHz
8Gb DDR2 PC2-6400 RAM
nvidia GTS 450 1GB video card
C: is a 160GB 7200rpm SATA drive
D: is a 500GB 7200rpm SATA drive
G: is a 500GB GoFlex drive used for backup
Windows 7 Home 64 bit Service Pack 1

I'm not sure what I'm looking for here, other than just confirmation that it's probably the processor that is the bottle neck in the problem I am describing. But, maybe it's something with my setup for LR.

Thanks for your time.

LR does not use the GPU, there is nothing a faster GPU can do for it.

An Athlon dual core is simply too old and slow for the file sizes generated by your 7D.
Its very close to the minimum system requirements needed to run LR, recommended is a quad core CPU and to get instant renders of editing your going to need an Intel i5 or i7.

Upgrading the CPU won't help either, there is nothing that will work in that socket that is fast enough, the BUS speed and RAM are too slow.

Thanks Moppie... exactly what I wanted to be sure of. *Does the "I'm getting a new computer dance"* err... after I talk to the wife, of course.

+1 on the CPU. I left AMD chips after 11 years of faithfulness. If I may, the best CPU I have ever bought for my builds ever is the i7 2600K. I do not have issues with slider adjustments when working in LR 4.1 I love seeing the windows task manager showing that LR actually uses all 8 of the threads.

Some people don't care much about overclocking but I think it's a wonderful option. I have 8 threads running at 4.74Ghz and surely is a godsend when processing files and video encoding.

Take a gander at my gear link in my sig then look under my computer equipment list. There you will find a link to my build to give you an idea of components that will get the job done. If you don't need an awesome video card, building your own PC will be a worthwhile, cost effective project in my honest opinion.

I also used to do AMD. When Sandy Bridge arrived, that brought me back to Intel. I built my one i72600K unit that is now a Hackintosh running OS 10.7.4. If I would to build a machine today, I would for with a Sandy Bridge i7 3930K 6 core CPU sitting in a LGA 2011 mobo such as a Gigabyte X79UD7. That has the latest chipset with quad channel memory, USB 3, and many more enhancements. To save a few bucks you can put in a 4 core LGA 2011 CPU and move to 6 core later.

Thanks for the input y'all... it's appreciated.