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I have a question: Previous systems with discrete GPU memory had some pretty insane memory bandwidths which helped them be way faster than software rendering. N
by AshleysBrain 13y ago
I have a question: Previous systems with discrete GPU memory had some pretty insane memory bandwidths which helped them be way faster than software rendering. Now GPU and CPU share memory. Doesn't that mean the GPU is limited to slower system RAM speeds? Can it still perform competitively with discrete cards? Or is system RAM now as fast as discrete-card bandwidth? If so does that mean software rendering is hardware-fast as well? Bit confused here...
- wmf 13y agoYes, these APUs are limited to fairly slow DDR3 RAM. It has been suggested that making the GPU part of the chip bigger wouldn't help because it would be bandwidth limited. There are a couple of possible solutions to this: The PS4 uses GDDR so it's more like a traditional GPU with a CPU added on. Intel's Iris Pro uses a large fast L4 cache. The Xbox One has some fast graphics RAM on chip. AMD will need to do something to increase memory bandwidth if they want to sell processors for more than $200.
- sliverstorm 13y agoIt's a trade-off. The off-chip GPU will have the most memory bandwidth and the most crunching power (larger thermal envelope). The on-chip GPU will have wildly superior latency, lower cost, and lower power consumption. It also has access to the on-die L2 cache now, although I'm not sure what that means for bandwidth- how does CPU L2 compare to GPU L2? High-end on-chip GPU's can compete with midrange off-chip GPU's.