What are the performance implications of Hyper-threading for single Nehalem+ CPU? I am choosing between two models of servers, the major difference between them being the the availability of Hyper-Threading.  Servers in question are SYS-E32-1 and SYS-E32-3  (an  brand) and use either Intel Xeon  or , both  ( Core-i Xeon CPU):   SYS-E32-1:       4c / 4t 3.2 GHz+ SYS-E32-3:       4c / 8t 3.4 GHz+   The big difference between them is that the first has 4 core/4 threads configuration, while the latter has 4 core/8 threads, due to Hyper-Threading being enabled.  I am going to run CentOS 6 and other OS guests on a CentOS 6 host with KVM virtualization. Currently I assign 1 virtual CPU per virtual machine, as that's enough for my current loads. Our normal load is the usual web services.  How much should the performance differ for me? Is it close to having twice more computing power or nearly the same computing power, distributed over twice more cores?
Can you help me with my capacity planning? This is a  about  Related:      I have a question regarding capacity planning. Can the Server Fault community please help with the following:   What kind of server do I need to handle some number of users? How many users can a server with some specifications handle? Will some server configuration be fast enough for my use case? I'm building a social networking site: what kind of hardware do I need? How much bandwidth do I need for some project? How much bandwidth will some number of users use in some application?
"Pick up something" or "pick something up"? Fix for word of power quest bug at Arcwind Point When I picked up the word of power at Arcwind Point, the quest didn't get removed from my quest log. If I select it, the arrow still points to the wall even though there is no word to collect anymore. The monks at High Hrothgar won't give me a new word power quest since they don't realize that I finished this one.  I can see in the Unofficial Elder Scrolls pages that this is a known issue.   My question is now, is there anything I can do about it? I don't want to reload a previous save since I have done much since it happened. I didn't realize until hours afterwards what had happened.   Note: I am on Xbox 360 so the Unofficial Dawnguard Patch is not an option. How coherent light is created for single slit experiment? How to determine the current widget's parent container (sidebar widget id) Addons: Only some .zips will install Why is it that if I go to install an add-on from User Preferences > Add-ons > Install from File... and choose a *.ZIP, some add-ons will install, while others will return me to the User Preferences with nothing having happened (as far as I can tell)?  Is there a specific file structure required in the .ZIP? I get many add-ons from GitHub, using the Download Zip button, and even there installation of the actual Zip file only works some of the time. Google spreadsheet sorting messes up cell comments I'm running into this weird problem with Google spreadsheets: if the cells have comments on them and I sort the spreadsheet, the rows sort but the comments stay in the same position, and don't move with the cells they're attached to.  In other words, the cells look like this:  A C  &lt;-- comment on this cell B   and then I sort by this column:  A B  &lt;-- comment remains on this cell (stays in position) C  &lt;-- comment should have remained attached to this cell   This means that sorting is completely broken and I can't use it at all, because I clearly need the cell comments to stay with the cell they're attached to.  Is this a bad bug in Google Spreadsheets, or am I missing something here? Two logos in beamer after certain frame Is there a (La)TeX distribution running on iPad? 80s-90s anime (movie or series) in which an armored girl exchanges age with a dying man on a beach Constructing a metric on a Lie Group By the end of The Force Awakens, who knows about Kylo Ren's family? I am trying to prove  $$\int\cos^n x \ dx = \frac{1}n \cos^{n-1}x \sin x + \frac{n-1}{n}\int\cos^{n-2} x \ dx$$  This problem is a classic, but I seem to be missing one step or the understanding of two steps which I will outline below.   $$I_n := \int\cos^n x \ dx = \int\cos^{n-1} x \cos x \ dx \tag{1}$$  First question: why rewrite the original instead of immediately integrating by parts of $\int \cos^n x \ dx$?  Integrate by parts with $$u = \cos^{n-1} x, dv = \cos x \ dx \implies du = (n-1)\cos^{n-2} x \cdot -\sin x, v = \sin x$$  which leads to  $$I_n = \sin x \ \cos^{n-1} x +\int\sin^2 x (n-1) \ \cos^{n-2} x \ dx \tag{2}$$  Since $(n-1)$ is a constant, we can throw it out front of the integral:  $$I_n = \sin x \ \cos^{n-1} x +(n-1)\int\sin^2 x \ \cos^{n-2} x \ dx\tag{3}$$  I can transform the integral a bit because $\sin^2 x + cos^2 x = 1 \implies \sin^2 x = 1-\cos^2 x$  $$I_n = \sin x \ \cos^{n-1} x + (n-1)\int(1-\cos^2 x) \ \cos^{n-2} x \ dx \tag{4}$$  According to Wikipedia as noted , this simplifies to:  $$I_n = \sin x \ \cos^{n-1} x + (n-1) \int \cos^{n-2} x \ dx - (n-1)\int(\cos^n x) \ dx \tag{5}$$  Question 2: How did they simplify the integral of $\int(1-\cos^2 x) \ dx$ to $\int(\cos^n x) \ dx$?  Assuming knowledge of equation 5, I see how to rewrite it as  $$I_n = \sin x \ \cos^{n-1} x + (n-1) I_{n-2} x  - (n-1) I_{n} \tag{6}$$  and solve for $I_n$. I had tried exploiting the fact that  $$\cos^2 x = \frac{1}{2} \cos(2x) + \frac{1}{2} $$  and trying to deal with $\int 1 \ dx - \int \frac{1}{2} \cos (2x) + \frac{1}{2} \ dx$  which left me with $\frac{x}{2} - \frac{1}{4} \sin(2x)$ after integrating those pieces. Putting it all together I have:  $$I_n = \sin x \ \cos^{n-1} x + (n-1) I_{n-2} x \left(-(n-1) (\frac{x}{2} - \frac{1}{4} \sin 2x) \right) \tag{7}$$  but I'm unsure how to write the last few terms as an expression of $I_{something}$ to get it to match the usual reduction formula of   $$\int\cos^n x \ dx = \frac{1}n \cos^{n-1}x \sin x + \frac{n-1}{n}\int\cos^{n-2} x \ dx$$ Which tag is used in the title of a question?   It does not seem to be the most popular It does not seem to be the first in the tagging order:   This question   is prefixed with NGINX (which is actually completely fine)  And it is tagged with "php nginx fastcgi magento" in the order of popularity.  Can we choose the tag to use in the title manually? Why is /tmp a symlink to /private/tmp on Mac OS X? In other words, why isn't /tmp just a regular directory, like on Linux or BSD? I understand how it works and I don't mind it, I'm just interested in the (historical?) reasoning behind it. Why is there a difference between ping "localhost" and ping "local IP address"? Using cmd and ping on Windows gave me the following results:   Pinging "localhost":       Pinging "192.168.0.10" (local IP address):     Aren't both situations exactly the same?   I mean, I'm pinging the same interface, the same machine and the same address. Why do I get such different results?  EDIT: Here is my ipconfig /all screen: What function satisfies $ f(x)+f\left(\frac{1-x}x\right)=x$ ? How to print all printable ASCII chars in CLI? Deactivate all \alt,\uncover in beamer (for printing) I have a big latex beamer that uses \alt, \uncover, ... to create "animations".  My goal is to deactivate all these commands temporary (let's say : just use the last state/slide each time there's this kind of thing) to print my document.  Is there a global command to do this or have I to do all this manually (comment manually the commands / or (simpler but still really long) suppress manually pages from the output) ?  Thanks very much in advance for your help. I'm running into this weird problem with Google spreadsheets: if the cells have comments on them and I sort the spreadsheet, the rows sort but the comments stay in the same position, and don't move with the cells they're attached to.  In other words, the cells look like this:  A C  &lt;-- comment on this cell B   and then I sort by this column:  A B  &lt;-- comment remains on this cell (stays in position) C  &lt;-- comment should have remained attached to this cell   This means that sorting is completely broken and I can't use it at all, because I clearly need the cell comments to stay with the cell they're attached to.  Is this a bad bug in Google Spreadsheets, or am I missing something here? Where do students who don't get into Hogwarts go?