I was benchmarking my WD 500 GB HDD in Ubuntu Disks several times and saw that the read speeds started at 140 MB/s, but it consistently would gradually decrease by a few MB/s with seemingly no floor. The same was for write speeds, but to a dramatically greater extent. What is the meaning of that? I am installing Ubuntu on it now; what might I expect the impacts will be on daily use as time goes on (i.e. how will that behavior manifest in daily use)?
I use HD Tune to measure performance of the hard drive.  The tests typically take 2-3 minutes and the transfer rate of a regular hard drive decreases dramatically as the test comes to a close.    However, the SSD drive performance stays the same over (pic below) the life of the test.  This happens on all my computers.  Why is that?
bordermatrix with blocks I need to write a complicated matrix, that has a structure as in the attached picture. In a situation where say a group (or at least a plurality) of men is being addressed — for example on a sign passed by many married men — which is correct?  &quot;Remind your wife.&quot;  or  &quot;Remind your wives.&quot; Spam iCloud Calendar Invitations Today I've suddenly received spam calendar invitation for $19.99 Ray Ban sunglasses (never subscribed, checked, searched or visited any related site, so clearly spam) and it has other visible email accounts within the invitation. I'm wondering if I should be worried whether my accounts been compromised or a simple email from anywhere just plops this in my calendar without review. Questions to be answered:  What should I check/setup in order to make sure my iCloud account is safe? How can I delete this invitation without sending a notification to the sender, so as to prevent them from knowing my email address is live? How can I prevent these notifications in the future?  Here's an image: If gravity isn't a force, then why do we learn in school that it is? I have studied some of Einstein's Theory of General Relativity, and I understand that it states that gravity isn't a force but rather the effects of objects curving space-time. If this is true, then why are we instructed in middle school that it is a force? error: parsing file '/var/lib/dpkg/status' near line 55497 package 'indicator-displex' After running an upgrade from Ubuntu 11.10 (Oneiric Ocelot) to 12.04LTS (Precise Pangolin), a window popped up saying that the upgrade failed and that I should run sudo dpkg --configure -a.  Running that command gave me:  sudo dpkg --configure -a dpkg: error: parsing file '/var/lib/dpkg/status' near line 55497 package 'indicator-displex':  blank line in value of field 'Description   Trying to run apt-get install -f gives me many dependency errors along with that same dpkg error. Given 4 integers, $a, b, c, d > 0$, does $\frac{a}{b} < \frac{c}{d}$ imply $\frac{a}{b} < \frac{a+c}{b+d} < \frac{c}{d}$? We were trying to come up with an easy way to generate a rational number in between two existing rational numbers with a fairly low numerator and denominator (the way we were doing this earlier was to find the average of the two rationals, but that results in a denominator of up to $c * d$. Does this inequality hold for all values of $a, b, c, d$? What is the best regular expression to check if a string is a valid URL? Does it make sense to say, "The speed of light varies?"  Some may say right off the bat "Yes, it changes as a wave passes through a different medium."  However, I'd like to say no, because when I hear someone say the speed of light, I always think of the constant $c$ (unless the medium is specified to not be a vacuum, but then it isn't $c$ anymore), not the speed of a particular wave.  To me, it makes more sense to say something like, "The speed of a particular wave varies." What is the correct way to state this in the professional world? And in general, when professional physicists say "the speed of light," are they referring to the constant or the actual speed of the wave? What does the "private" modifier do? Considering "private" is the default access modifier for class Members, why is the keyword even needed? Where did the pardon come from? In the  episode  (S04E08), Barristan Selmy is presented with a Royal Pardon supposedly signed by the late Robert Baratheon for Ser Jorah Morment by a lowly boy of Meereen.  However, it is a bit confusing to me as where this actually came from.  Is this the same pardon that Jorah had towards the beginning of the series while Robert was actually alive, or is this pardon one that Tywin actually forged and wrote in a previous episode (remember he asks Mace Tyrell for a quill after learning about Dany's recent actions and allies).  It being from Tywin makes sense but this point is brought up by Jorah and then defeated a sentence later as he himself states it is not a forged Pardon.    So which is it and why would Jorah say it is not a forged copy if it indeed is? Schengen visa category required for job interview How to re-download Lion to create a VMWare Fusion 4 virtual machine? I have a MacBook with Lion installed.  I bought VMWare Fusion 4 because I want to create a Lion VM.  As far as I can tell I need to point VMWare to the Lion installer that is downloaded from the App Store, but that file deleted itself after Lion was installed.  How do I re-download the Lion installer (and keep it around) to create a VMWare Fusion 4 virtual machine? What is the most popular open source password manager which I can use on a Ubuntu machine or preferably across Ubuntu/Windows machines with some form of data compatibility. If there is a free web based version, that would be even more preferable. Subversion Obliterate feature I was just thinking of writing a shell script to implement the obliterate functionality in an easy to do way (externally, using the suggested way, but automated).  Here's what I had in mind:  On the client   svn list -R &gt; file-list. filter file-list in several ways like grep to create a file "files-to-delete", something like a set of grep XXX  file-list&gt;&gt;files-to-delete. transfer files-to-delete to the server using scp.   On the server   Dump the repository svnadmin dump /path/to/repos &gt; repos-dumpfile, this can be kept as a backup too. Filter the dump file, for each word in "files-to-delete", do: cat repos-dumpfile | svndumpfilter exclude $file &gt; new-dumpfile Create a new repository and load the new file to it svnadmin create new-name; svnadmin load new-name &lt; new-dumpfile   Would this work? How can it fail? Any other ideas? Express $x^8-x$ as a product of irreducibles in $\Bbb Z_2[x]$ Express $x^8-x$ as a product of irreducibles in $\Bbb Z_2[x]$.  Work so far:  $$x^8 - x = x(x^7 - 1) = x(x - 1)(x^6+x^5+x^4+x^3+x^2+x+1)$$  From here, I think the Zeros of an Irreducible over a splitting field Theorem would be the method. I am unsure how to proceed Is the reason why the time evolution operator is unitary based on purely physical arguments, i.e. that the physical processes that an isolated system undergoes shouldn't depend on any particular instant in time (homogeneity of time); thus two experimenters who conduct the same experiment starting from the same initial state, but at different times, should have the same probability amplitude for that state?! Or is there some mathematical argument as well?  Also, is the reason why the time evolution operator is linear implied by the superposition principle (as an arbitrary state can be expressed as a linear combination of basis states the operator should act linearly as otherwise the state as a whole would evolve differently to the superposition of states that it was initially represented by)?! Do Ryzen 3 2200u laptops with Vega 3 work out of the box with major Linux distros? $ not defined using jQuery in WordPress LIKE uses index, CHARINDEX does not? How long can a flag remain active? I have flagged the following question as a duplicate.    Now I want to know: after how long time will it be stated as active?  I do not have problem with anything here. I just want to know after how long time the request (of a duplicate question) will automatically be rejected or approved.  OK, I got the things, so it will remain active until moderators will have a look at it...  But don't you think we should have a limit that after a certain number of days this kind of request will be dropped (or cancelled)?