RE: GCC 8.3.0 vs. 9.0.1

2019-05-09 Thread Steven Winfield
Thanks, everyone, for your comments. I guess if something looks too good to be true then it usually is! Steven. (P.S. Apologies for the email disclaimer - it is added by our mail server, not my mail client, and its exclusion list is on the fritz)

Re: GCC 8.3.0 vs. 9.0.1

2019-05-07 Thread Andres Freund
Hi, On 2019-05-07 10:32:45 -0700, Andres Freund wrote: > pgbench -i -q -s 96 && pgbench -n -c 8 -j 8 -T 100 -P1 possibly also worthwhile to note: Adding -M prepared (which I think phoronix doesn't specify) makes this considerably faster... Greetings, Andres Freund

Re: GCC 8.3.0 vs. 9.0.1

2019-05-07 Thread Andres Freund
Hi, On 2019-05-07 10:28:16 -0700, Peter Geoghegan wrote: > On Tue, May 7, 2019 at 10:06 AM Tom Lane wrote: > > Given the described test setup, I'd put basically no stock in these > > numbers. It's unlikely that this test case's performance is CPU-bound > > per se; more likely, I/O and lock

Re: GCC 8.3.0 vs. 9.0.1

2019-05-07 Thread Andres Freund
Hi, On 2019-05-07 16:14:43 +, Steven Winfield wrote: > (Apologies if this isn't the right place to post this) Seems right. > A few days ago a blog post appeared on phoronix.com[1] comparing GCC 8.3.0 > against 9.0.1 on Intel cascadelake processors. > A notable difference was seen in the

Re: GCC 8.3.0 vs. 9.0.1

2019-05-07 Thread Peter Geoghegan
On Tue, May 7, 2019 at 10:06 AM Tom Lane wrote: > Given the described test setup, I'd put basically no stock in these > numbers. It's unlikely that this test case's performance is CPU-bound > per se; more likely, I/O and lock contention are dominant factors. > So I'm afraid whatever they're

Re: GCC 8.3.0 vs. 9.0.1

2019-05-07 Thread Tom Lane
Steven Winfield writes: > A few days ago a blog post appeared on phoronix.com[1] comparing GCC 8.3.0 > against 9.0.1 on Intel cascadelake processors. > A notable difference was seen in the PostgreSQL benchmark (v10.3, pgbench, > read/write, more detail below), both when compiling with

GCC 8.3.0 vs. 9.0.1

2019-05-07 Thread Steven Winfield
Hi, (Apologies if this isn't the right place to post this) A few days ago a blog post appeared on phoronix.com[1] comparing GCC 8.3.0 against 9.0.1 on Intel cascadelake processors. A notable difference was seen in the PostgreSQL benchmark (v10.3, pgbench, read/write, more detail below), both