6 ms·
What other laptop ships with LPDDR4X clocked at 4267? I agree though that being closer to the cpu isn't having any appreciable effect on latency, but being sold
by gameswithgo 6y ago
What other laptop ships with LPDDR4X clocked at 4267?
I agree though that being closer to the cpu isn't having any appreciable effect on latency, but being soldered close to the cpu probably does make it easier for them to hit that high clock rate.
- wmf 6y agoTiger Lake laptops such as the XPS 13.
- jeffbee 6y agoAs WMF mentions, Tiger Lake laptops like my Razer Book have the same memory. It is not appreciably closer to the CPU in the Apple design. In Intel's Tiger Lake reference designs the memory is also in two chips that are mounted right next to the CPU.
- danaris 6y agoAnd (genuine question) how do the Tiger Lake laptops compare with the M1 MacBooks thus far?
- skavi 6y agoAnandTech has decent benchmarks for both Tiger Lake [0] and M1 [1]. [0]: https://www.anandtech.com/show/16084/intel-tiger-lake-review-deep-dive-core-11th-gen https://www.anandtech.com/show/16084/intel-tiger-lake-review... [1]: https://www.anandtech.com/show/16252/mac-mini-apple-m1-tested https://www.anandtech.com/show/16252/mac-mini-apple-m1-teste...
- jeffbee 6y agoThe outcome seems to depend greatly on the physical design of the laptops. The elsewhere-mentioned Dell XPS 13 has a particularly poor cooling design, which is why I chose the Razer Book instead. Despite being marketed in a very silly way to gamers only, it seems to have competent mechanical design.
- SAI_Peregrinus 6y agoGamers are likely to run their systems with demanding workloads, for hours, with a color-coded performance counter (FPS stat). They'll notice if it throttles. They're particularly demanding customers, and there's quite a bit of competition for their money.
- wil421 6y agoHow common are laptops for gamers? I always build my windows boxes but I’m a casual gamer.
- SAI_Peregrinus 6y agoI'm not sure. I know they've been getting more popular with the increased power of laptops and the ability to use external GPUs (via Thunderbolt 3). I'd guess desktops are more common, but some people will have both.
- valuearb 6y agoThe raw CPU performance of the M1 is about 15% faster single core, and 50% faster multicore, while using nearly half as much power.
- sliken 6y agoMind running a memory latency benchmark on your Razer Book? Does it run linux by chance?
- wmf 6y agoYou can compare https://www.anandtech.com/show/16084/intel-tiger-lake-review-deep-dive-core-11th-gen/4 https://www.anandtech.com/show/16084/intel-tiger-lake-review... and https://www.anandtech.com/show/16252/mac-mini-apple-m1-tested https://www.anandtech.com/show/16252/mac-mini-apple-m1-teste...
- celrod 6y agoI have a Dell XPS 13 with a Tiger Lake CPU. Out of curiosity, running the script: > ./two_or_three N = 1000000000, 953.7 MB starting experiments. two : 30.6 ns two+ : 39.6 ns three: 45.1 ns bogus 1422321000 This is much slower than the times Lemire reported for the M1. `two+` is 62% of the way between `two` and and `three`, vs 88% for the M1. EDIT: Adding `-march=native` didn't really change the results, which makes sense given that it's a memory benchmark.
- gspr 6y agoStrange on my XPS 15 7590 (i7-9750H), I get N = 1000000000, 953.7 MB starting experiments. two : 12.8 ns two+ : 13.7 ns three: 19.5 ns bogus 1422321000
- celrod 6y agoYeah, that is strange. Why was it so slow? Trying on a desktop with a 7900X, I get N = 1000000000, 953.7 MB starting experiments. two : 17.7 ns two+ : 19.1 ns three: 26.4 ns bogus 1422321000 This is again close to 50% slower than your time, but nearly twice as fast. I'll try again on the laptop and make sure I don't have other processes running.
- gspr 6y agoStrange. I suppose the compiler shouldn't matter much here, right? At any rate, I'm using GCC 10.2.1.
- celrod 6y agoI'm using gcc 10.2.0. I tried clang 11 and got more or less the same thing, so it doesn't seem to make much of a difference. Neither did messing with flags, like (I tried -fno-semantic-interposition -march=native and a few others).
- celrod 6y agoI just ran it again, and got more or less the same results: N = 1000000000, 953.7 MB starting experiments. two : 29.7 ns two+ : 36.5 ns three: 43.8 ns This surprises me. Normally, it does very well in most benchmarks I run. Looking a little closer at the script, it loads numbers from "random", a vector of 3 million `Int` (this is hard coded, separate from `N`). This vector is about 11.4 MiB. The Tiger Lake CPU has 12 MiB of L3 cache (same as your i7-9750H), so it barely fits. Meanwhile, the L1 cache is 48 KiB and the L2 cache is 1.5 MiB -- huge compared to most recent CPUS, and a lot of benefit in most benchmarks, but at the cost of higher latency. https://www.anandtech.com/show/16084/intel-tiger-lake-review-deep-dive-core-11th-gen/4 https://www.anandtech.com/show/16084/intel-tiger-lake-review... Skylake's L3 latency was 26-37 cycles, and in Willow Cove's (Tiger Lake), it is 39-45 cycles. That difference by itself isn't big enough to account for the difference we're seeing, so something else must be going on.