Hi,
I have one setup with one rb750g that does hotspot for 150 active users.
When the active users reaches 80, the cpu load ii 100% almost all the time.
Clients have real IP-s, so there is no NAT for them, but if i disable conntrack, internet is not working.

So, i want to switch to a x86 machine
(HP/COMPAQ PROLIANT DL380 G3)
cpu: 2 x Intel Xeon 2400 Mhz / 512 Kb cache
ram: 1024 Mb DDR-ECC
hdd: 2 x 36 Gb SCSI
controller : Compaq Smartarray SCSI RAID
optics: CD-ROM
case: rack 2U
---- that will be around 115EUR + Mikrotik lvl4 licence

Of course, maybe a cheaper solution is to split the users on 2 rb750g so that will cost only 47EUR

What do you recommend ?

PS:
One solution to my problem may be the ability so switch off conntrack, but with that off,the internet is not working.

conntrack is needed for NAT, I have public IPs with no conntrack.

Yes, but conntrack is used for hotspot too...
If i disable conntrack, users with public ip won't have internet