"DMA limited to UDMA33" is there any knob?

Good people,

on my system (7.0-CURRENT as of 7/24 18:42 EST) I receive following
message during boot:

ad0: DMA limited to UDMA33, device found non-ATA66 cable
ad0: 28615MB <IC25N030ATMR04 0 MOAOAD0A> at ata0-master UDMA33

Since there is no cable (drive attached directly to the connector
mounted on the piece of PCB), I wonder whether there are any overriding
knobs. ATA controller is VIA8235:

atapci0: <VIA 8235 UDMA133 controller> port
0x1f0-0x1f7,0x3f6,0x170-0x177,0x376,0xfc00-0xfc0f at device 17.1 on pci0

atapci0_at_pci0:17:1:      class=0x01018a card=0x120514ff chip=0x05711106
rev=0x06 hdr=0x00
    vendor   = 'VIA Technologies Inc'
    device   = 'VT82xxxx EIDE Controller (All VIA Chipsets)'
    class    = mass storage
    subclass = ATA

According to the data sheet drive is capable of UDMA100.

Any suggestions will be greatly appreciated.
-- 
Alexandre "Sunny" Kovalenko (Олександр Коваленко)