More Core i7 trichannel "failure" from "thiefs"

[justthefax]

Anybody notice the big jump in latency going to tri-channel? Around 15% worse latency

Thanks for the reply.

If I understand correctly, we should all notice the difference between dual and triple channel, but it's very likely that if we use non-multicore applications that the difference will be very small. The bandwidth that is added because of the extra channel is to provide enough bandwidth to fully cover the 8 threads, but is 'overkill' when using in single/dual threaded applications.

Now, that only leaves the everest bandwidth problems. As far as I know, the Lavalys Everest program is quite accurate when it comes to calculating the memory bandwidth and latency, but in tests I've seen the difference still is only 500MB/s:




Only two tests actually show the difference between dual and triple channel, which probably is the correct performance scaling.

[xVeinx]

Anybody notice the big jump in latency going to tri-channel? Around 15% worse latency

And if you look, his timings have changed

[Shintai]

Anybody notice the big jump in latency going to tri-channel? Around 15% worse latency

The clocks and settings of the memory aint the same either.

Plus we dont know the BIOS version.

[JumpingJack]

Anybody notice the big jump in latency going to tri-channel? Around 15% worse latency

Yeah, huge.... trichannel has a whole 25 ns of latency... how terrible.

[Drwho?]

Anybody notice the big jump in latency going to tri-channel? Around 15% worse latency

Actually, the problem is not the hardware here, it is the software, I have my friend Ronen working with the everest guys, I am not sure of the status, but I know from sure that the processor affinities does not allow the max bandwith to be always measured properly.

I will check and update you guys later, Monday.

In the mean time, this 2 numbers shows that Core i7 is the 1st having a real integrated memory controler .. (kidding! don t shoot!)

If you use Sandra, you will see that Banwidth is better with 3.

Francois

[massman]

The crysis is loading times. Most of the restriction is HD based.

Seriously? I don't really find that a propper way to compare hardware, although these are more real-life measurements than raw numbers.

Actually, the problem is not the hardware here, it is the software, I have my friend Ronen working with the everest guys, I am not sure of the status, but I know from sure that the processor affinities does not allow the max bandwith to be always measured properly.

Good, let's hope the preliminary support gets turned into full support sooner than later.

[Shintai]

Seriously? I don't really find that a propper way to compare hardware, although these are more real-life measurements than raw numbers.

Yes, seriously. xtreview just stole the numbers and posted it as their own. (And thereby completely skipping all explanations).

But as said, you can read it yourself.



Also a note that this aint benched on the newest versions to say it mildly.