Hello, On 02/25/2010 12:15 PM, Yuhong Bao wrote: >> (following thread from the ATA side) I'm with Greg on this. USB2.0 is >> quite slow on today's standard and most 64bit machines now have IOMMU >> of some kind anyway. > > Except that unfortunately, Intel with Lynnfield and Clarkdale decided > to do market segmentation on the VT-d feature. > This could be done because both have an integrated northbridge. > With Lynnfield, the very common Core i5 750 CPU do not support VT-d, > but the Core i7 800 series does. > With Clarkdale, the very common Core i3 500 series do not support VT-d, > but the Core i5 600 series does, except the 661. > Not to mention that in the Core 2 generation, VT-d was available only > on Q35/Q45/X38/X48 chipsets. Arghhh.... I hate when intel pulls this type of 'product differentiation' stunts. At any rate, I'm doubtful swiotlb'ing for usb2.0 would be noticeable at all. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
