<br><br><div class="gmail_quote">2013/2/27 sandeep kumar <span dir="ltr"><<a href="mailto:coolsandyforyou@gmail.com" target="_blank">coolsandyforyou@gmail.com</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr"><div><div style="font-family:arial,sans-serif;font-size:13px">>"volatile" only say to the compiler to not put the variable in a register.</div><div style="font-family:arial,sans-serif;font-size:13px">
>Could i ask why does you want to mesure the speed of the RAM ? Is it to study the NUMA behavior of the machine?</div><div style="font-family:arial,sans-serif;font-size:13px"><br></div></div><div style="font-family:arial,sans-serif;font-size:13px">
In development phase of the board, we are trying to measure RAM performance gain while changing type of the RAM.</div><div style="font-family:arial,sans-serif;font-size:13px">The standard benchmark tools are giving us the Cache performance only. So we want to try some method to measure RAM performance.</div>
</div></blockquote><div><br></div><div>ok.</div><div>The answear is hardware-dependent, some hardware may have a way to disable the cachability (but will probly need to be in the kernel).</div><div><br></div><div>But to skeep the hardware dependencie, you need to read a part of memory that is not cached.</div>
<div>The best way is to do the test at boot time when the caches are cold. I dont think that a user-space application could do this in precise way, since it cannot know the physical address it address....</div><div><br></div>
<div>Doing a small "boot" code and booted directly (without grub) could give some precise numbers. </div><div>You will also need to space yout read request (128*8 byte for example), since most cache caches a line while you have read only one word.</div>
<div><br></div><div>Hope i helped.</div><div>regards.</div><div> </div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div><div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Feb 27, 2013 at 2:30 PM, Karaoui mohamed lamine <span dir="ltr"><<a href="mailto:moharaka@gmail.com" target="_blank">moharaka@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br><br><div class="gmail_quote"><div>2013/2/27 sandeep kumar <span dir="ltr"><<a href="mailto:coolsandyforyou@gmail.com" target="_blank">coolsandyforyou@gmail.com</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr"><div>>><span style="font-family:arial,sans-serif;font-size:13px">I am not sure but what if you make the variable as a volatile?</span></div><div><font face="arial, sans-serif">Hey i tried. But still is showing the same time for int & volatile int.</font></div>
<div><font face="arial, sans-serif"><br></font></div></div></blockquote><div><br></div></div><div>"volatile" only say to the compiler to not put the variable in a register.</div><div>Could i ask why does you want to mesure the speed of the RAM ? Is it to study the NUMA behavior of the machine?</div>
<div><div>
<div><br></div><div><br></div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><font face="arial, sans-serif"></font></div><div><font face="arial, sans-serif">Thanks</font></div>
<span><font color="#888888"><div><font face="arial, sans-serif">Sandeep<br></font><div><span style="font-family:arial,sans-serif;font-size:13px"><br>
</span></div></div></font></span></div><div><div><div class="gmail_extra"><br><br><div class="gmail_quote">On Tue, Feb 26, 2013 at 6:50 PM, ankur dwivedi <span dir="ltr"><<a href="mailto:ankurengg2003@gmail.com" target="_blank">ankurengg2003@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">I am not sure but what if you make the variable as a volatile? <br><br><div class="gmail_quote"><div><div>On Tue, Feb 26, 2013 at 5:01 PM, sandeep kumar <span dir="ltr"><<a href="mailto:coolsandyforyou@gmail.com" target="_blank">coolsandyforyou@gmail.com</a>></span> wrote:<br>
</div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div><div dir="ltr">Hi All<div>In performance benchmark tools, When we profile read/write timings mostly, those read/writes are done to cache only.</div>
<div><br></div><div>I want to measure my DDR(RAM chip) performance.</div><div>
So i want to make sure, every read/write should happen to DDR RAM chip only.</div><div><br></div><div>How can i achieve this...Any ideas/suggestions...?<span><font color="#888888"><br clear="all"><div><br>
</div>-- <br>With regards,<br>Sandeep Kumar Anantapalli,<br>
</font></span></div></div>
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<br></div></blockquote></div><span><font color="#888888"><br><br clear="all"><br>-- <br>Thanks<br><br><span style="color:rgb(0,0,153)">Ankur Dwivedi</span><br><span style="color:rgb(0,0,153)"></span><br>
</font></span></blockquote></div><br><br clear="all"><div><br></div>-- <br>With regards,<br>Sandeep Kumar Anantapalli,<br>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br>With regards,<br>Sandeep Kumar Anantapalli,<br>
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