Sizing Up Servers: Intel's Skylake-SP Xeon versus AMD's EPYC 7000 - The Server CPU Battle of the Decade?
by Johan De Gelas & Ian Cutress on July 11, 2017 12:15 PM EST- Posted in
- CPUs
- AMD
- Intel
- Xeon
- Enterprise
- Skylake
- Zen
- Naples
- Skylake-SP
- EPYC
Database Performance: MySQL Percona Server 5.7.0
For database benchmarking we still base our testing on Percona server 5.7, an enhanced drop-in replacement for MySQL. But we have updated our SQL benchmarking once again. This time we use Sysbench 1.0.7, which is a lot more efficient than the previous 0.4 and 0.5 versions. As a result, the measured numbers are quite a bit higher, especially on the strongest systems. So you cannot compare this with any similar Sysbench-based benchmarking we have done before.
For our testing we used the read-only OLTP benchmark, which is slightly less realistic, but still much more interesting than most other Sysbench tests. This allows us to measure CPU performance without creating an I/O bottleneck.
As expected, the EPYC 7601 can not deliver high database performance out of the box. A small database that can be mostly cached in the L3-cache is the worst case scenario for EPYC. That said, there are quite a few tuning opportunities on EPYC. According to AMD, if you enable Memory Interleaving, performance should rise a bit (+10-15%?). Unfortunately, a few days before our deadline our connection to the BMC failed, so we could not try it out. In a later article, we will go deeper into specific tuning for both platforms and test additional database systems.
Nevertheless, our point stands: out of the box is the EPYC CPU a rather mediocre transactional database CPU. With good tuning it is possible EPYC may pass the Xeon v4, but the 8176 is by far the champion here. It will be interesting to measure how EPYC compares in the non-transactional databases (Document stores, Key-value...) but transactional databases will remain Intel territory for now.
Typically when high response times were reported, this indicated low single threaded performance. However for EPYC this is not the case. We tested with a database that is quite a bit larger than the 8 MB L3-cache, and the high response time is probably a result of the L3-cache latency.
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TheOriginalTyan - Tuesday, July 11, 2017 - link
Another nicely written article. This is going to be a very interesting next couple of months.coder543 - Tuesday, July 11, 2017 - link
I'm curious about the database benchmarks. It sounds like the database is tiny enough to fit into L3? That seems like a... poor benchmark. Real world databases are gigabytes _at best_, and AMD's higher DRAM bandwidth would likely play to their favor in that scenario. It would be interesting to see different sizes of transactional databases tested, as well as some NoSQL databases.psychobriggsy - Tuesday, July 11, 2017 - link
I wrote stuff about the active part of a larger database, but someone's put a terrible spam blocker on the comments system.Regardless, if you're buying 64C systems to run a DB on, you likely will have a dataset larger than L3, likely using a lot of the actual RAM in the system.
roybotnik - Wednesday, July 12, 2017 - link
Yea... we use about 120GB of RAM on the production DB that runs our primary user-facing app. The benchmark here is useless.haplo602 - Thursday, July 13, 2017 - link
I do hope they elaborate on the DB benchmarks a bit more or do a separate article on it. Since this is a CPU article, I can see the point of using a small DB to fit into the cache, however that is useless as an actual DB test. It's more an int/IO test.I'd love to see a larger DB tested that can fit into the DRAM but is larger than available caches (32GB maybe ?).
ddriver - Tuesday, July 11, 2017 - link
We don't care about real world workloads here. We care about making intel look good. Well... at this point it is pretty much damage control. So let's lie to people that intel is at least better in one thing.Let me guess, the databse size was carefully chosen to NOT fit in a ryzen module's cache, but small enough to fit in intel's monolithic die cache?
Brought to you by the self proclaimed "Most Trusted in Tech Since 1997" LOL
Ian Cutress - Tuesday, July 11, 2017 - link
I'm getting tweets saying this is a severely pro AMD piece. You are saying it's anti-AMD. ¯\_(ツ)_/¯ddriver - Tuesday, July 11, 2017 - link
Well, it is hard to please intel fanboys regardless of how much bias you give intel, considering the numbers.I did not see you deny my guess on the database size, so presumably it is correct then?
ddriver - Tuesday, July 11, 2017 - link
In the multicore 464.h264ref test we have 2670 vs 2680 for the xeon and epyc respectively. Considering that the epyc score is mathematically higher, howdoes it yield a negative zero?Granted, the difference is a mere 0.3% advantage for epyc, but it is still a positive number.
Headley - Friday, July 14, 2017 - link
I thought the exact same thing