Hi guys!
so I wanna upgrade my computer to the point where I can have fast renders with cycles. I do not sculpt much.
I don’t have enough money to buy a really good computer at the time 
I have an intel core 2 quad 2.66 processor with 2.5 GB of ram. also an Nvidia GeForce 9800 GTX+ with 512 MB of memory (I know, very old :P)
I found a GPU that is cheap and (I hope) works with cycles’ viewport renderer (my current GPU doesn’t work) called NVIDIA GeForce GT 420. do you guys think I should buy it? and should I upgrade the RAM as well?
A RAM upgrade never hurts, especially when you consider that the more you have, the larger the image file size can be (hence, the larger you can make your image). One thing I discovered on my old laptop was that I didn’t have enough ram to hold a 2550 x 3300 image, but it would hold a 1700 x 2200 image. (In case you’re wondering, that’s the difference between 8.5 in x 11 in at 200 pixels and 300 pixels per inch respectively.) So what kept happening is when it got to a certain point in the render, it would crash the system. My newer laptop had a just a bit more memory on it, and was easily able to hold the larger image with no problems.
I don’t have any experience with the others myself. But a RAM upgrade certainly won’t hurt 
thanks! I will definitely take that under consideration 
however, I tend to render with 1920 x 1080 for everything 
(pics and vids)
ram will depend on your op sys (32 bit is limited to 4 gig I think) but even win 7 has limits over the range (eg home/pro etc)
as for the card I think you’d be wasting your money!! (save a bit longer if you can). There is a thread on here with lots of info on gpus, so dig it(them) out and have a good read before buying
will the RAM upgrade speedup the rendering process? because that is my main priority
Short: No.
Not fully true, but the speedup will be nearly not noticeable unless you’re currently using the pagefile to it’s fullest already.
Rendering is pure CPU power, if you use Cycles with CUDA, pure GPU power.
Memory may not help much with speed, but it can still help even when rendering at 1080. The final image may be small enough to fit, but it’s not impossible for the resources required to produce it to fill it up quickly. The final image may require only 50mb to display, but you could easily have hundreds of mb in textures, sim caches or animation data to produce it.
As already advised, the video card would get you more speed if you are rendering in cycles and I don’t think you’ll be able to squeeze much more performance out of a Core2 chip even with the added memory. On a limited budget, upgrading your processor is probably the last thing you should do, as it will likely require a new board, memory, psu etc.
so basically what you guys are saying is that I should get a whole new computer XD
My old CPU was a C2Q-Q9550, from your specs I guess you have got a Q8400.
The Q9550 is very easy to OC. It has a stock clock of 2.83GHz, mine ran for over 5 Years with 3.4GHz with a lowered Voltage even to the “auto” setting.
This might be a nice performance boost if you can get your hands on a nice cheap used 9550.
I also would stay away from the GF 420. Not only is it barely faster than the CPU, in terms of hardware it’s quite ancient and it’s CUDA compute capability might soon not be enough to run GPU renderers.
You could look for a used GTX560 for instance, you get them quite cheap and they are a multiple faster than the 420.
Or you save up some money for a new state of the art system that will last a few years again.
It’s really just a question of your budget and how much time you want to save, or how much money it is worth to you.
ok, so I decided to save up to get a good computer that would last for some years just like arexma said. Which let me to thinking if I should use renderfarm.fi for the current time. What do you guys know about it? does it slow your computer down because other people are using it? (that’s how I understand it :P) and does it support cycles?
I don’t have much experience with render farms, but my understanding is that the client software on your computer is like any other service or application in that it will use some resources, but the rendering itself is supposed to be limited to idle time.