as smudgee said, it depends on the used plugins. And the hard drive arrangement. Also Nucleo is slow when I use a plugin that uses only one core. I'm not 100% sure, but I think it was the Magic Bullet plugin. In such cases you can't do anything to speed up rendering except of network rendering.
About Nucleo: I'm talking about Nucleo Pro 2 together with After Effects. Depending on the source files, you can export your Premiere project to After Effects and render it out. I really recommend to test it again, because of the following advantages:
-background rendering: you continue working on your project/comp, while Nucleo does the render job. Isn't that phantastic? You really have to experience this, it changes (speeds up) your workflow dramatically.
-fast rendering. After Effects is blocked, as normal, and Nucleo renders super-fast with all cores used. I made some tests (maybe posted here somewhere) and observed around 30% faster render times with a 6400 Core2Duo.
-3D rendering: you're working on a composite, and before going into After Effects, you must render out the 3D images. With Nucleo, you simply drag and drop the 3D project into the Nucleo render queue, and immediately start working with After Effects while the images drop in. No waiting anymore.
And 2 GB of RAM is enough for Nucleo to work. I have not encountered any problems with RAM blocking or something. When you close AE, Nucleo closes also, and your machine is "free". If I worked commercially, Nucleo Pro 2 would be the most wanted software to buy to increase productivity. So, think about it . . .
Well anyway, you surely have a powerful machine and your everyday work must have become easier, with or without Nucleo. I wish you all the best for your company and your work.