Hi,
I tried two motherboards who claim to support SATAe but none of them works. Details are here.
Because currently there are very few SATAe devices, does anyone know any motherboards which can definitely make the SATAe devices work?:colbert:
Hi Raja,
Now I am trying to debug my SATA express device on this board (Z97-WS) and I need some help.
I know the SATA express ports can be used as two regular SATA ports. I tried to move my boot disk to connect to different SATA ports. However the 4 SATA express ports didn't work. All the...
Hi everyone,
Now I want to test my SATA express device.
I have two hosts. One is GA-Z97x-Gaming and the other one is ASUS Z97-WS which both have SATA express ports. However, after some efforts, I can not make either of them work. I am wondering whether anyone here has any...
Hi everyone,
I have read many interesting technical articles from Anandtech about different SOC's video performance. To help myself to better understand them in the future, I just want to find a general technical tutorial about how the video data is processed and rendered to the screen. For...
Hi, thanks for your information.
I am not sure why we still need 800MHz when processor is idle.But I know Intel recent processors implement very good clock and power gating for idle state on a per physical core basis. So are you sure the processor will not be clock gated during idle?:colbert:
Yes. That's also my concern. But I really do not really know which one(threshold voltage or peripheral) is the real bottleneck in system nowadays.:hmm:
Hi,
Everyone here talks about overclocking. Obviously the thing stopping us from overclocking is the temperature.But I just feel curious why we also can't undercloking too far:rolleyes:
What I can think of possibly are two reasons:
1. Some peripheral devices will not work when CPU frequency...
Hi everyone,
I have read many interesting technical articles from Anandtech about different SOC's video performance. To help myself to better understand them in the future, I just want to find a general technical tutorial about how the video data is processed and rendered to the screen. For...
Finally I got it:D:cool: It is just because of the reason I mentioned above. The DDR3 memory is so fast that only one core's memory bound workload can not saturate it and CPU resource is always the bottleneck.
However, when I try to run 8 memory bound workloads on my 8 cores at the same time...
I have checked my memory. It's 64bit DDR3 1600MHz DIMMs(4GB X 2). I think even older DDR memory can read or write multiple data word in the same clock cycle,right?(Because it can transfer at both rising and falling clock edge). So DDR3 should be very fast. In one second , it should be able to...
I tried. It's the same thing. Get a little confused.... On my machine, the memory bound task seems to scale pretty well with the CPU frequency .... This must have something to do with the design
Thanks. I will try to add that simple tasks. But FYI, for the memory access, it's definitely not "idle". The OS will attribute it to be as utilized. However, for the disk access, it is attributed as "idle". I am pretty sure about this:D
I personally do not think the memcpy() function will be CPU limited even when the CPU frequency is 1.6GHZ....:\ What's the role of the CPU during memory chuck copy? It should not require a lot of CPU computation,right?
:eek:No. I just commented the run() function in main and I have found the CPU core utilization is 0% from top command:(. And as I mentioned before, the benchmark was scaling as expected on my Core 2 Dou(E8400) Dell workstation while the behavior is totally different on my new i3770K machine.
Glad that you are willing to take a look at my source code:
I pin the task on specific core and scale the frequency of that core.
I have also ran a benchmark called lmbench. I use command
(not sure whether you know this benchmark or not) to test the memory bandwidth. I do see the reported...
Thanks:\ I will try to do more experiments to verify. Anyway, I think the memory bound task and CPU bound task should have different response to the CPU frequency scaling.:eek:
Hi Cerb:D. What you said about the cache frequency scaling makes sense.
However,I have done some more experiment. Generally, I have two programs , one of which use busy loops and sleep to achieve 50% utilization on one core, another of which use memcpy function and sleep to achieve 50%...
Thanks for your reply. The data moved is 20000*20000 int type. I believe it should be much bigger than the L3 cache,right? What I thought before was also that cache would scale while memory would not
Hi,
I have an Intel i7 i3770K. I have generated a benchmark by myself. Generally, it will use memcpy function to move a big chuck of data in memory from one place to another then go to sleep for a fixed amount of time.
I pin the benchmark on one core. Then I scale the core's frequency from...
At last I have found what happened. It has nothing to do with HT.:)
When the cores are idle, the frequency is always minimum as long as not all frequencies are set to be a fixed value. So results are only meaningful when the CPU is loaded.
After I ran a busy loop and pin it on specific cores...
Yes.Your HT suggestion sounds promising. I will look into that. I just started to learn the Intel-pstate driver yesterday from the google+ post. But still believe the old acpi driver should at least work. Probably HT causes the problem:rolleyes:
Thank you. Actually I have done a lot of research about the CPU frequency scaling in Linux. This is the first time I have heard about the "pstate governor"...:rolleyes: So maybe I should try to build 3.10 kernel by myself. But I think the old governors probably should still be supportedo_O
Thanks. That post is very helpful. I will take more time to read. But maybe scaling governors should be still working as long as it is in the kernel?:confused: Above all, from what I learnt, to change a frequency of one core, substantially, all I need to do is to write something into the MSR of...
Yes.What you said might be true. I am a researcher and I just need to do some research on how to control the frequency of different cores though different frequency of different cores might not be useful as you said.
But anyway, I think the hardware now should be like different core has...
My CPU is Ivy-bridge i3770K. My OS is ubuntu 12.04 with kernel 3.5.0-34.
I used to play cpufreq driver a lot. But its behavior is weird on this machine.
It has four physical cores. With SMT enabled, there are totally 8 logical CPUs. And CPU 0 and CPU 4 are in the same physical core...
Hi, thanks. My system is ubuntu 12. I just used the apt-get to download the lm-sensors 3.3.1 version. Then sensors only show the following temp value:
Even a sensors-detect command didn't add anything. Does that mean lm-sensors doesn't support my hardware? My goal is to read the core voltage. Or...
Hi,
In Windows, we always use CPU-Z. But is there any tool in Linux which can show the current core voltage?
My CPU is Ivy-bridge i7 3770K.
I know the i7z is useful. However, it only shows the frequency ,no voltage.
Another tool is c2ctl. It works on my Core 2 machine(successfully show...
OK. I have found there is no "current" sensor type supported by Android software development... http://developer.android.com/guide/topics/sensors/sensors_overview.html
:oops:
Hi,
With the current sensor, we can measure the energy drain by the phone. From what I learnt, most phones do not have such sensors because it appears to be not useful for the app developers. And it looks like iphone 3GS has such sensor. So do you guys know any model with the current...
During the frequency scaling or overclocking, will the cache's frequency also change? If so, is there any specific relationship? I know probably the memory frequency will not change:$
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