Shaping Download traffic

[denizv]

Hi

I'm trying to figure out traffic shaper for 9 months now.
I literally have 3 queues ( low, medium and high). High is for games with should have lowest latency. Low for torrenting and medium for browsing and http video.
I dont want to put any download limit any queues but bursting caused by http video increases latency in high queue for 1-2 seconds and torrenting have more severe effects. Furthermore bursting causes hard limit on lan download to be exceeded. Hard limit on lan download is 10% lower than my actual download speed ( i measured tediously). Sometimes bursting traffic go above the limit i set on lan to the actual limit by isp.
I have found workaround though, i put low and medium queues in 1 group and set its upper limit to 80% and further limiting low queue. I tried all the schedulers, different ones have different effect but all of them giving me pretty much same results.

My hardware: dual Intel 82574L nic supermicro server with managed cisco switch.
I'm thinking my hardware is superior enough to manage this traffic (8/1 mbit adsl). Then other option is , it is impossible or very hard to manage download queues on priority base, we have to put hard limits on queues, without it, latency spikes are inevitable. Am i right or there are other ways?.
Ps. I don't have any problems with upload queues because i have direct control over them. 4th queue is ACK queue if you wondered