I said I crochet faster, but that’s because of all those speedy stitches in crochet, like double and triple crochet! I’ve never compared the speed of single crochet to knitting. I wonder! I have no idea. I’ve been crocheting since I was 4, and I’m pretty fluid at it, but I’ve done more knitting in my life.
I just clocked my knitting speed last night for the first time, so your question is timely! I definitely hit 51 sts/minute, and I thought I hit 54 sts/minute, but I’m not sure I clocked that last one right. In any case, that was my best, of a handful of attempts. I think that’s pretty darn fast. I just did a little online research, and it sounds like the very fastest knitters out there do 60 sts./minute. I usually knit at a much more mellow pace though, more like 40 sts/minute. That’s my natural pace, and I like to take it easy! It’s not about speed, for me, but enjoying the task! Good heavens, I wouldn’t want to try to knit an entire garment in my super-speedy mode! LOL! 
My fastest purling was 40 sts/minute, but I think if I kept trying I could get 45, because I kept missing stitches.
I found I was much faster on my size 4 needles with smooth merino yarn, then I was on my size 9’s with acrylic. It made a HUGE difference! It’s making me think I might want to try out those Addi Turbo needles everyone raves about. I’ve never even tried them!
Maybe I should change my Knitting Geek Code to say SPM+++ (Stitches per Minute = unusually fast)? I’ve never had anyone gawk at my knitting speed; but then I don’t usually knit at that top speed. I think because I tend to knit slower, I’ll keep it at SPM++!
In general, I think it’s unusual for a beginner to knit faster than 30 spm, and more common to be in the teens or twenties.
Amy