On Fri, May 17, 2019 at 07:57:32PM -0400, D. Hugh Redelmeier via talk wrote:
For the CPU's Lennart was talking about, the modern CPU is a little faster, but no enough to notice
<http://hwbench.com/cpus/intel-core-i7-8550u-vs-intel-core-i7-3820qm>
(The i7-8550u is in the NUC; the i7-3820qm is my guess at what Lennart's ThinkPad W530 has.)
You guess correctly. The desktop machine runs an i7-3960X. It certainly would not be a big leap in performance, and if you touch anything with graphics, the quadro K2000M will beat the intel graphics easily. :)
Desktops are a bit different. But I would not expect even a factor of two difference in comparable processors of these two generations.
Which processor models were/are in your (Giles') two systems?
- DDR4 (8th gen) is faster than DDR3 (required by 3rd gen). But most programs don't seem to be affected much by this. Does your program bust the (rather large) L2 cache?
As far as I know, DDR4 has more bandwidth but also higher latency, so different work loads are affected differently.
- 3rd gen i5's often have half the cores of 8th gen i5's. This may make a big difference. But Python programs often don't exploit multiple cores.
Well 3rd gen is usually 4 core (occationally 2) and 8th gen is 6 core.
- a few instructions have been added, but I don't imagine that they affect your python program. AVX2 for floating point, for example.
My best guess is that the program sped up due to (NVMe?) SSD vs HDD.
Yeah that could easily drop 20m to 5m or more.
Perhap AMD flaws haven't been discovered yet. But the current score shows AMD ahead.
My take on rowhammer is that it is a bug in the DRAM chips and should be fixed under warranty. They just don't meet specs. Exploiting rowhammer (as opposed to just making a machine go wrong) requires knowing the memory mapping, and that can be facilitated by some processor bugs.
-- Len Sorensen