430 reputation
414
bio website blog.piechotka.com.pl
location Munich, Germany
age 25
visits member for 4 years, 1 month
seen Apr 11 at 17:46

Feb
20
comment Paranoid Parent: “WiFi safe for baby?”
@Virtlink - microwave have emitter of range 800-1000 W. Typical leakage from microwave is 1W. WiFi have 100 mW output. It's more like standing next to a candlelight then being in oven.
Feb
12
comment Why do Jumbo Frames hurt latency?
AD PMTUD: I thought that it's combination of DF + Fragmentation Needed (or Packet Too Big in IPv6) - TCP/IP stack being concerned with throughput tries to discover the MTU (if there is more then one hop as you wrote) but UDP/IP would either use right size of have longer time with 'classical' frames if the FN/PTB would be passed to application. Is it correct description of PMTUD (sorry - I haven't touch it for a while and some details might got blurry).
Feb
12
accepted Why do Jumbo Frames hurt latency?
Feb
11
comment Why do Jumbo Frames hurt latency?
It does not quite answer (or at least I don't see it). For TCP it will hurt the latency of connection initiation (Path MTU discovery) but it should not hurt the UDP as there is no Path MTU dicovery there - packet might be either dropped or not. Also it should not hurt the latency after the Path MTU was discovered as at this point no datagram which would exceed MTU would be sent.
Feb
11
asked Why do Jumbo Frames hurt latency?
Feb
7
accepted How to unmount (safely remove) USB disk/pendrive from Windows 8 after opening file in Metro Application
Nov
26
comment What stops an internet router from sniffing my traffic?
@FrankThomas - this is true only if SMTP does not use TLS (by STARTTLS etc.). I thought most servers does not accept unencrypted SMTP from clients (however - I would not my first disappointment in people's approach to security).
Nov
9
awarded  Popular Question
Oct
26
awarded  Excavator
Oct
26
revised What is svchost.exe (LocalSystemNetworkRestricted) when I see it in the Resource Monitor in Windows vista and why is it slowing me down?
Fix the link - the old one refers to disambiguation page
Oct
26
suggested suggested edit on What is svchost.exe (LocalSystemNetworkRestricted) when I see it in the Resource Monitor in Windows vista and why is it slowing me down?
Aug
30
comment Why would a RAMdisk be used today?
And another is when you have large amount of I/O but you can allow it to be volatile. The normal operation of cache have periodic flushes of the data (otherwise it could never be written to disk so saved file would not be, well, saved) so it can saturate in the background with heavy I/O by temporary files.
Aug
30
comment Why does RAM have to be volatile?
@Val It depends where user sits. From POV of program the file (disk) can be randomly accessed - that is not the same as POV of os. On the other hand from POV of memory controller the RAM is read in burst and usually multiple burst are read for efficiency (I believe it has something to do with parallelism of addressing in DRAM but I may be wrong). Given that DRAM can be used in FPGA there memory controller can be 'an user'.
Aug
25
comment What is the largest size of a 640x480 JPEG?
Also if you deal with specialized systems the packing could be done on-chip without any cycle loss (drop every 4th byte is trivial to implement in specialized unit and might be worth the effort if the operation is common).
Jul
13
awarded  Yearling
Jul
13
comment My /tmp folder isn't a partition but has fixed size. Why?
The problem is with /tmp not /dev/shm (the latter is almost not used).
Jul
13
answered My /tmp folder isn't a partition but has fixed size. Why?
Jul
8
comment Why have CPU manufacturers stopped increasing the clock speeds of their processors?
@demonofnight: It would be too much to say "every time you need to (...) jump". Unconditional direct branches pose no control hazard so they don't count out of conditional branches ~95%-99% are predicted by various techniques (data based on some paper basing on SPEC). Direct branches do pose the problem if the target is not yet in register and there is misprediction of it. I am not sure what you mean by 'fork the code' or 'clear the memory' but contexts switches should not be executed so often (interrupts and possibly I/O).
Jun
28
comment Windows 7 unreasonable ram usage
"Free RAM is only needed for the rare cases where RAM is needed and the operating system cannot transition RAM from one use to another" - wouldn't it make the RAM allocated for interrupted routine and therefore not really free?
May
29
comment Can I make a video not downloadable?
@AK4749: Well - the user have to have the decoder in the first place (which is probably unlikely because you would severely limit the userbase - and since no stream is using it no one have the initiative to buy one) AND the decoder outputs only to trusted source (the connection to monitor would need to be encoded.