Huh wow, I guess I'm behind the times. Didn't know they made that big of a jump within ARMv7. This makes me curious to look at the datasheets.
From what I can tell, the i.MX53[1] has a 64 bit AXI @ 200mhz. The Exynos5[2] on the other hand, has 64bit AXIs and also a ton of optimizations. The LCD spec says it operates off of a 200mhz AXI so I wouldn't be surprised if the Exynos5 uses dual 200mhz AXIs for memory. It's tough to tell how much of that 20 times translates to the clock speeds and the rest to optimizations. I agree the A15 is just a sign of things to come since ARMv8, although it has legacy stuff, ARM still gets to improve a lot more on the architecture specifically for servers.
For comparison, these guys [3] say 12.8 GB/S which kinda sounds ridiculous. If it's true, they really are in range of Intel. The Sandy Bridge Xeon E3-1220 boasts a theoretical 21 GB/s @ a whopping 80 watts (although the high end E7-8870 [4] is a fucking monster. At this point I can't even begin to think how they compare with all of Intel's memory stuff). The number are clearly within the ballpark, we'll just have to see a real world case. I'm curious about how well GCC and the kernels utilize all the unique processor features and optimizations. If it's mostly down to market forces, Intel's 96% market share might make it a long and difficult journey to an ARM Linux kernel optimized as well for a server environment as x86/x64 ports.
I'm too lazy to check what that assembly code is but if it uses NEON PLD optimizations (NEON is definitely in Exynos5) that may give a speed bump in memcpy (even if you preloaded the buffers) because those optimizations would use L1/L2 cache intelligently. It's hard to tell without looking at the code and diving into i.MX53's feature set more whether that played a factor. * I was thinking of malloc and free, they are system calls because of paging. Memcpy is a straight pointer to pointer copy, except maybe for whatever that assembly code does.
Time to just find a fluffy article on this topic [5]
From what I can tell, the i.MX53[1] has a 64 bit AXI @ 200mhz. The Exynos5[2] on the other hand, has 64bit AXIs and also a ton of optimizations. The LCD spec says it operates off of a 200mhz AXI so I wouldn't be surprised if the Exynos5 uses dual 200mhz AXIs for memory. It's tough to tell how much of that 20 times translates to the clock speeds and the rest to optimizations. I agree the A15 is just a sign of things to come since ARMv8, although it has legacy stuff, ARM still gets to improve a lot more on the architecture specifically for servers.
For comparison, these guys [3] say 12.8 GB/S which kinda sounds ridiculous. If it's true, they really are in range of Intel. The Sandy Bridge Xeon E3-1220 boasts a theoretical 21 GB/s @ a whopping 80 watts (although the high end E7-8870 [4] is a fucking monster. At this point I can't even begin to think how they compare with all of Intel's memory stuff). The number are clearly within the ballpark, we'll just have to see a real world case. I'm curious about how well GCC and the kernels utilize all the unique processor features and optimizations. If it's mostly down to market forces, Intel's 96% market share might make it a long and difficult journey to an ARM Linux kernel optimized as well for a server environment as x86/x64 ports.
I'm too lazy to check what that assembly code is but if it uses NEON PLD optimizations (NEON is definitely in Exynos5) that may give a speed bump in memcpy (even if you preloaded the buffers) because those optimizations would use L1/L2 cache intelligently. It's hard to tell without looking at the code and diving into i.MX53's feature set more whether that played a factor. * I was thinking of malloc and free, they are system calls because of paging. Memcpy is a straight pointer to pointer copy, except maybe for whatever that assembly code does.
Time to just find a fluffy article on this topic [5]
[1] http://www.freescale.com/files/32bit/doc/data_sheet/IMX53IEC...
[2] http://www.samsung.com/global/business/semiconductor/file/pr...
[3] http://www.maximumpc.com/article/news/samsung_details_exynos...
[4] http://ark.intel.com/products/53580/Intel-Xeon-Processor-E7-...
[5] http://www.theregister.co.uk/2011/10/20/details_on_big_littl...