Project 1: Linshen Xiao

README.md

@@ -1,10 +1,82 @@
 **University of Pennsylvania, CIS 565: GPU Programming and Architecture,
 Project 1 - Flocking**
 
-* (TODO) YOUR NAME HERE
-* Tested on: (TODO) Windows 22, i7-2222 @ 2.22GHz 22GB, GTX 222 222MB (Moore 2222 Lab)
+* LINSHEN XIAO
+* Tested on: Windows 10, Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz, 16.0GB, NVIDIA GeForce GTX 970M (Personal computer)
 
-### (TODO: Your README)
+## Screenshot
 
-Include screenshots, analysis, etc. (Remember, this is public, so don't put
-anything here that you don't want to share with the world.)
+A screenshot of the boids:
+
+![](images/boids.gif)
+
+## Performance analysis
+
+* Framerate change with increasing # of boids for naive, scattered uniform grid, and coherent uniform grid (with and without visualization)
+
+![](images/Withvisualize.png)
+
+Boids | Navie | Scattered uniform grid | Coherent uniform grid
+:---|:---:|:---:|:---:
+5000 | 156.2 | 397 | 401.8
+10000 | 55.7 | 481.6 | 455.9
+50000 | 2.8 | 278.6 | 341.1
+100000 | 0.7 | 149.5 | 185.2
+500000 | ? | 21.9 | 35.3
+
+![](images/Withoutvisualize.png)
+
+Boids | Navie | Scattered uniform grid | Coherent uniform grid
+:---|:---:|:---:|:---:
+5000 | 210.5 | 810.4 | 728.0
+10000 | 63.4 | 1174.7 | 1231.8
+50000 | 2.8 | 450.2 | 553.4
+100000 | 0.7 | 205.6 | 294.9
+500000 | ? | 22.3| 40.2
+
+As the number of boids grows, the FPS may always decrease(with some small exception), that's because more data needs to be computed if the number of boids increase.
+
+Improvement: Coherent uniform grid > Scattered uniform grid > Naive
+
+Framerate change with increasing block size
+
+![](images/Blocksize.png)
+
+Blocksize | Coherent uniform grid
+:---|:---:
+16 | 228
+32 | 309
+64 | 318.2
+128 | 307.6
+256 | 326.4
+512 | 316.9
+
+The change of block size does not affect the performance dramatically, but we can still see that block size 32 is still better than block size 16.
+
+## Questions
+
+* For each implementation, how does changing the number of boids affect performance? Why do you think this is?
+
+As the number of boids grows, the FPS will decrease, that's because more data needs to be computed if the number of boids increase.
+
+* For each implementation, how does changing the block count and block size affect performance? Why do you think this is?
+
+The change of block count and block size does not affect the performance dramatically, but it has some improvement before 32.
+
+* For the coherent uniform grid: did you experience any performance improvements with the more coherent uniform grid? Was this the outcome you expected? Why or why not?
+
+Yes. We can see the great improvement when the number of boids > 50000. Coherent uniform grid sort the array to skip a searching step to improve the performance.
+
+* Did changing cell width and checking 27 vs 8 neighboring cells affect performance? Why or why not?
+
+![](images/27vs8.png)
+
+Boids | 27 Cells | 8 Cells
+:---|:---:|:---:
+5000 | 412.8 | 401.8
+10000 | 482.6 | 455.9
+50000 | 450 | 341.1
+100000 | 303.2 | 185.2
+500000 | 97.8 | 35.3
+
+Yes. When the boids' amount is huge, though 27 cells needs to iterates more neighbors, the number of boids needs to be interated is less, so a large amount of time of computing distance is saved.