PCI Express Transactions  – Relaxed Ordering
	• Allocate USWC buffers to permit the GPU to optimize requests by setting the Relaxed Ordering attribute – permits Read completions to pass downstream Posted Writes which are potentially draining slowly – lowers GPU read latency permitting a stalled engine to proceed doing useful work more quickly • GPU driver will use an appropriate programming model so that relaxed ordering does not cause coherency issues – a GPU engine’s Read Completion can not be dependent on GPU context that may be in flight from the CPU issued as Posted Writes