Lightroom 4 1:1 preview question

For those that select multiple raw files (mine are from either a 7D or 60D) and tell Lightroom to generate 1:1 previews, how should this affect my cpu usage? The other night I selected around 30 raw images and while generating the previews, my cpu usage was spiking rapidly to max for the duration of process. Should it be using that much processing power to do this? Thanks for any info.

Yep. entirely normal. Building previews takes a lot of CPU activity and contrary to popular misconception, not a whole lot of memory.

I tested this today, I'll just quote my previous post:

Stone 13 wrote in post #15241228
I just did a quick test on my Core i5 laptop with 8gb ram, 256GB SSD and 500GB 7200 RPM hard disk.

My config is: Installation files, LR Catalog and ACR Cache on the SSD with raw files on the 500GB hard disk. I select 500 files and generated 1:1 previews. It took around 30 minutes and never used more than 800MB of memory and CPU usage never exceeded 20%. Performance could always be better, but for what it does, I consider LR4 pretty efficient.

Your CPU usage will reflect all the processes that are active, not just LR, so It can be normal for the usage to spike up, depending on what else is running. I typically have multiple programs sharing my Quad Core CPU, so as long as I can do anything at all while LR is rendering, I'm happy.

Good info. Thanks! The reason I even noticed it was that I was on a game website that lets you play a cheesy online billiards game and the graphics were a bit choppy. When I pulled up the task manager and looked at performance, I understood why.