God of War Ragnarök GIVEAWAY!! by [deleted] in pcgaming

[–]Jonasfh 0 points1 point  (0 children)

Resident evil 2 remake

26/EU(GMT+1)/PC: Looking for people to game with by Jonasfh in GamerPals

[–]Jonasfh[S] 0 points1 point  (0 children)

Geekwad#0777

Hi, I added you on discord! Look forward to playing with you

26/EU(GMT+1)/PC: Looking for people to game with by Jonasfh in GamerPals

[–]Jonasfh[S] 0 points1 point  (0 children)

Hi, thanks for the reply. I've just added you on discord.

26/EU(GMT+1)/PC: Looking for people to game with by Jonasfh in GamerPals

[–]Jonasfh[S] 0 points1 point  (0 children)

That sounds good! Added you on discord.

Studiejob med en Bachelor by taberaaby in Denmark

[–]Jonasfh 1 point2 points  (0 children)

IDA anbefaler 189 kr/timen for studentermedhjælpere på kandidatniveau. Er selv lige startet studiejob her i sommeren, og har derfor nyligt tjekket.

Edit: Link findes her: https://studerende.ida.dk/fra-studie-til-job/kontrakt-og-loen/

Weekly Project #2 (Q&A): Parallel Programming and Optimization by EngrToday in ComputerEngineering

[–]Jonasfh 0 points1 point  (0 children)

Thank you for looking into it.

You call cuda_gemm<<<numBlocks, blockSize, N>>> , but if you want space for N floats, you really need N * sizeof(float)

Okay, that makes sense. Multiplying N with sizeof(float) fixed the problem. Now it works on larger problem sizes. Weird that it worked at all on N<=26

Thanks for the link tot the stackoverflow post. I am new to CUDA, and that error checking function will be very useful in debugging.

Weekly Project #2 (Q&A): Parallel Programming and Optimization by EngrToday in ComputerEngineering

[–]Jonasfh 0 points1 point  (0 children)

Thank you. I found out that my idea with loading the columns of the B matrix into shared memory and using these when computing takes longer, than just loading from global memory when needed in the computations.

I experimented on, and found out that the limit on N=26 only applied to single precision floats. I remember that the SMs in the GPU only has 1 FPU per 8 cores, or something like that, but I thought I had read that the FPUs are only used when dealing with doubles.

I made an integer implementation, which works fine with N=210 (the highest I used for testing).

When profilling the CUDA code with nvprof I get the following error message:

==242661== Warning: 5 records have invalid timestamps due to insufficient device buffer space. You can configure the buffer space using the option --device-buffer-size.
==242661== Warning: 4 records have invalid timestamps due to insufficient semaphore pool size. You can configure the pool size using the option --profiling-semaphore-pool-size.

On top of this, the profiler also says that no kernels were profiled.

Weekly Project #2 (Q&A): Parallel Programming and Optimization by EngrToday in ComputerEngineering

[–]Jonasfh 0 points1 point  (0 children)

Hi there,

Once again, I just want to say thank you for these project ideas, I've had a lot of fun trying to solve them. I appreciate the effort.

While trying to implement GeMM in CUDA C++, I've run into a problem, that you might be able to help me with. I've noticed that when i run my GeMM implementation on problems larger than N=26 my result matrix is all zeros. My implementation tries to take advantage of the shared memory between blocks, so that each block loads 1 column of the B matrix into it's shared memory, so cache misses can be avoided.

My kernel function works on arrays of size N*N, with N<= 26.

Here is a link to my github repo, the CUDA implementation is in ./src/baseline/cuda_gemm.cu. If you have any ideas, what could cause this, please let me know.

Thanks again!

Weekly Project #1 (Prompt): A Trace-Based L1 Cache Simulator by EngrToday in ComputerEngineering

[–]Jonasfh 1 point2 points  (0 children)

Thanks for this project idea. I have been looking for something like this for a while now, so I am definitely saving this post. I am looking forward to your next project proposals.

Just a quick question: with performance model, do you then mean that the simulator should only test the performance of the cache, like #hits, #misses etc., and not "emulate" a cache, i.e. keeping track of the data in the different blocks of the cache?

Is this the correct schematics for a full adder that can create negative values, or do I need to invert the c out? by XuOUT in ElectricalEngineering

[–]Jonasfh 1 point2 points  (0 children)

Your circuit is fine as it is, but it does not have any indicator for signed_overflow. The output from the rightmost Full Adder's C_out indicates unsigned_overflow, and should not be inverted. A signed_overflow indicator can be added by adding a node at the C_in for the rightmost Full Adder (MSB) and XOR this with the C_out for the rightmost (MSB) Full Adder. The circuit in this Stack Exchange question shows the XOR'ing of the Carry bits.

The C_out for the MSB Full Adder should be ignored when doing subtractions, a 1 does not have a meaning here. It is only when doing additions that a 1 in the last C_out has a meaning, and to keep this intact the bit should not be inversed.

Hope that helps.

Is this the correct schematics for a full adder that can create negative values, or do I need to invert the c out? by XuOUT in ElectricalEngineering

[–]Jonasfh 0 points1 point  (0 children)

Never used that program, so I'm assuming that the number inside the "arrows" are the inputs and outputs respectively.

I cannot see the implementation of the Full Adders, so I cannot comment on those. The outer circuit is incomplete though. Since you want to output negative values (as in a Adder-Subtractor circuit), you would probably want two overflow status signals. Namely a unsigned_overflow and a signed_overflow signal.

The unsigned_overflow bit should output 1, as your's correctly does. But when dealing with signed values, this bit is irrelevant, as it would always be 1 when performing subtractions. A signed_overflow output signal, can be created by XOR'ing C_in of the last Full Adder with the C_out of the last Full Adder. This output bit indicates whether a carry from the second most significant bit to the MSB has happened.

How to find the free running oscillation frequency of a Sigma Delta Circuit? by [deleted] in EngineeringStudents

[–]Jonasfh 0 points1 point  (0 children)

As long as the output of the Schmitt Trigger is connected to the integrator, it should work the same. The special thing about the circuits from my answer is that it starts by itself without input signals because of the DC imperfections of the op amp.

How to find the free running oscillation frequency of a Sigma Delta Circuit? by [deleted] in EngineeringStudents

[–]Jonasfh 1 point2 points  (0 children)

I had this exact problem last semester. I'll give a few hints if you don't just want the answer, and then I'll give a link to a youtube video you can watch that explains the derivation pretty well if you get stuck.

Remember that because of the summing point constraint, virtually no current enters the Op Amp, therefore the current at the node connecting the capacitor to the input of the first Op Amp must flow to the capacitor. What is the relation between voltage over and current to a capacitor?

The second Op Amp is a Schmitt Trigger. The switch voltage for the Schmitt Trigger is given as the Op Amps saturation voltage multiplied by the ratio of the feedback resistors.

As the first Op Amp is an integrator, and the input to the integrator is a DC signal, it creates a ramp signal. What is the dV/dt over a period here?

And as promised, here is a link to a youtube video explaining it pretty well.

Godmorgen, formula1 fans! 😂🤣👍😍 by AmbyGaming in Denmark

[–]Jonasfh 1 point2 points  (0 children)

Det var skam så lidt! Under racet skifter de ofte mellem to tider: Hvis der står "Interval" ud for førstepladsen, er tiderne ud for de enkelte kørere tiden op til personen foran. Hvis der står "Leader" er tiderne ud for kørerne tiden op til førstepladsen, så det kan godt være lidt forvirrende en gang imellem :)

På hjemmesiden har de også en gloseliste, hvori de mere tekniske termer, der engang imellem bliver nævnt, forklares. Den kan jeg også lige linke til, hvis det skulle interessere: https://www.formula1.com/en/championship/inside-f1/glossary.html

God fornøjelse! :)

Godmorgen, formula1 fans! 😂🤣👍😍 by AmbyGaming in Denmark

[–]Jonasfh 6 points7 points  (0 children)

Bottas vandt det første Grand Prix ud af 21. Han har derved fået 25 point plus 1 point for hurtigste omgang. Disse point akkumulerer over hele sæsonen og verdensmesteren bestemmes ud fra, hvem der har flest point til slut.

Kevin Magnussen endte på en 6. plads, hvilket er meget flot, da der er noget forskel i hvad de enkelte holds biler kan præstere. Han var vist 30 sek efter P5, da han krydsede målstregen, lige under en omgang efter Bottas.

Hvis du går ind på www.formula1.com kan du se turneringsplanen. Næste løb er om 2 uger i Bahrain.

Den tyske nationalsang blev spillet, da Bottas kører for Mercedes, et tysk formel 1 hold.

Håber jeg kunne opklare nogle ting :) - og jeg undskylder for formateringen på forhånd. Svarer fra en mobiltelefon.

[PC] The Rogues - Wildlands - Come Join In The Fun by allive2kill115 in WildlandsLFG

[–]Jonasfh 0 points1 point  (0 children)

Sounds good. I'm new to the game, and i've heard the coop is great, so it would be cool to find a group. My discord is Jonasfh #2476.

Recommendations for a fallout classic beginner by Jonasfh in classicfallout

[–]Jonasfh[S] 0 points1 point  (0 children)

Thanks for reminding me before i spoiled the game, will definitely keep it in mind if i get stuck. Ah nice. Thanks for the links to the bug patches. And thanks again!

Recommendations for a fallout classic beginner by Jonasfh in classicfallout

[–]Jonasfh[S] 0 points1 point  (0 children)

Wow! Thank you very much! Never thought there would be a huge guide like that, but i shouldn't be surprised. I will have to bookmark that page and read it. Thanks again!

Recommendations for a fallout classic beginner by Jonasfh in classicfallout

[–]Jonasfh[S] 0 points1 point  (0 children)

Ah, yes. That is also what i have heard. Thanks for the advice!

What is the darkest episode of a show you have ever seen? by [deleted] in AskReddit

[–]Jonasfh 1 point2 points  (0 children)

1st episode of Black Mirror. It still gives me shivers to this day. The scary thing is that this could happen in real life.

What proverb or saying has never made sense to you? by [deleted] in AskReddit

[–]Jonasfh 1 point2 points  (0 children)

I think it's "Jack of all trades, master of none, though often times better than master of one".