Questions tagged [slowdown]
235 questions
22
votes
9 answers
how does one identify why a website is slow?
I was asked this question once at an interview:
"Suppose you own a website where the server is at some remote location. One day, some user calls/emails you saying the site is abominably slow. How would you identify why the site is slow? Also, when…
Anish Ramaswamy
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18
votes
3 answers
Hyper-threading... made my renderer 10 times slower
Executive summary:
How can one specify in his code that OpenMP should only use threads for the REAL cores, i.e. not count the hyper-threading ones?
Detailed analysis: Over the years, I've coded a SW-only, open source renderer (rasterizer/raytracer)…
ttsiodras
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15
votes
1 answer
Why does iterative elementwise array multiplication slow down in numpy?
The code below reproduces the problem I have encountered in the algorithm I'm currently implementing:
import numpy.random as rand
import time
x = rand.normal(size=(300,50000))
y = rand.normal(size=(300,50000))
for i in range(1000):
t0 =…
Ottokar
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14
votes
1 answer
Why transposing a CUDA grid (but not its threadblocks) still slowdowns computation?
EDIT: It seems that, at least in this case, transposing the grid has a negative effect on the L2 Cache Bandwidth. This was obtained from the visual profiler. The reason why is not clear to me yet.
I have come to a GPU computing situation in which…
Cristobal Navarro
- 326
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12
votes
3 answers
WatiN Dispose() is really slow
My WatiN tests have suddenly gotten REALLY slow when I dispose the Internet Explorer object.
Here's my setup...
* Windows 7 (Evaluation Build 7100)
* Internet Explorer 8 (Version 8.0.7100.0)
* WatiN (Version 2.0.10.928)
This is strange because the…
Garth
- 533
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9
votes
1 answer
Visual Studio 2015 Very Slow File Opening?
I just downloaded VS15 2015 Community on my Windows 10 machine, and just installed all of the default packages.
For whatever reason, if I try to open a javascript file, or nearly any other extension, it takes about a full 15-20 seconds for it to…
jkteddy77
- 127
- 2
7
votes
1 answer
Multi-processing in Python: Numpy + Vector Summation -> Huge Slowdown
Please don't be discouraged by the long post. I try to present as much data as I can, and I really need help with the problem :S. I'll update daily if there are new tips or ideas
Problem:
I try to run a Python code on a two core machine in parallel…
Lodrik
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7
votes
2 answers
does vim read the whole file into memory
When I open a file, does vim read it all into memory? I experienced significant slowdowns when I open large files. Or is it busy computing something (e.g., line number)?
dacongy
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6
votes
1 answer
Do additional, unused CSS definitions slow down browsers?
After working with many CMSes and cutting up many HTML designs, when I saw SilverStripe's use of CSS, I was converted.
Essentially, that it would be a waste to change IDs in
tags depending upon the page you were on, and that changing the…
SoreThumb
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6
votes
1 answer
How to simulate slow connection with Javascript?
I've got a request for a research website which will test user's behavior when doing repetitive tasks on a normal and slow Internet connections.
I'm wondering if there are any JS libraries I could use for bandwidth throttling in the different…
Goran Stoyanov
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6
votes
1 answer
Enough to call Children.Clear on a WPF canvas to get rid of old controls before adding new ones?
I am experimenting with WPF and re-implementing my old maze screensaver.
My code basically adds a bunch of images to the canvas, building up a grid, 64x64 pixel images side by side, to cover the entire canvas. Then I "animate" movement in the maze,…
Lasse V. Karlsen
- 380,855
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6
votes
1 answer
Why is php script slowing down?
I was working on migration scripts which selects data from one MySQL database and import through doctrine into another MySQL database. The problem was that after every chunk of created entities, my scripts slowed down.
first 100 articles takes about…
Tomáš Tibenský
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5
votes
4 answers
Android- download file + status bar notification slowing down phone
I currently have an asynctask which downloads a mp3 from a server. When the user starts to download it, a status bar notification is created. This displays the progress of the download in real time. My only concern is that the phone slows down…
Splitusa
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5
votes
7 answers
Mysql select on indexded column slowdown on large tables
I have two tables : A - 301 columns ( 1st one named a1 int(11) Primary Key, 2nd to 301th - double(15,11) ) & B - 33 columns ( 1st one - b1 int(11) Unique Key, 2nd One - b2 varchar(100) Primary Key, ... , 33rd - b33 int(11) MUL ).
Both A & B have ~…
ayesha129
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5
votes
4 answers
PHP script gets progressively slower (file reader)
I have a script that, when put against a timer, gets progressively slower. It's fairly simple as all it does is reads a line, checks it then adds it to the database, then proceeds to the next line.
Here's the output of it gradually getting…
DCD
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