More fields/columns
There are a ton more available fields which XFCE4 Task Manager doesn't support, e.g. (it's a complete htop output but I don't want to filter it):
Display options Main PID PID - Process/thread ID
Header layout I/O USER STATE - Process state (S sleeping, R running, D disk, Z zombie, T traced, W paging, I idle)
Meters PRIORITY PPID - Parent process ID
Screens NICE PGRP - Process group ID
Colors M_VIRT SESSION - Process's session ID
M_RESIDENT TTY - Controlling terminal
M_SHARE TPGID - Process ID of the fg process group of the controlling terminal
STATE MINFLT - Number of minor faults which have not required loading a memory page from disk
PERCENT_CPU CMINFLT - Children processes' minor faults
PERCENT_MEM MAJFLT - Number of major faults which have required loading a memory page from disk
TIME CMAJFLT - Children processes' major faults
PROCESSOR UTIME - User CPU time - time the process spent executing in user mode
STATE STIME - System CPU time - time the kernel spent running system calls for this process
RBYTES CUTIME - Children processes' user CPU time
WBYTES CSTIME - Children processes' system CPU time
IO_PRIORITY PRIORITY - Kernel's internal priority for the process
Command NICE - Nice value (the higher the value, the more it lets other processes take priority)
STARTTIME - Time the process was started
PROCESSOR - Id of the CPU the process last executed on
M_VIRT - Total program size in virtual memory
M_RESIDENT - Resident set size, size of the text and data sections, plus stack usage
M_SHARE - Size of the process's shared pages
M_TRS - Size of the text segment of the process
M_DRS - Size of the data segment plus stack usage of the process
M_LRS - The library size of the process (calculated from memory maps)
ST_UID - User ID of the process owner
PERCENT_CPU - Percentage of the CPU time the process used in the last sampling
PERCENT_MEM - Percentage of the memory the process is using, based on resident memory size
USER - Username of the process owner (or user ID if name cannot be determined)
TIME - Total time the process has spent in user and system time
NLWP - Number of threads in the process
TGID - Thread group ID (i.e. process ID)
PERCENT_NORM_CPU - Normalized percentage of the CPU time the process used in the last sampling (normalized by cpu count)
ELAPSED - Time since the process was started
CTID - OpenVZ container ID (a.k.a. virtual environment ID)
VPID - OpenVZ process ID
VXID - VServer process ID
RCHAR - Number of bytes the process has read
WCHAR - Number of bytes the process has written
SYSCR - Number of read(2) syscalls for the process
SYSCW - Number of write(2) syscalls for the process
RBYTES - Bytes of read(2) I/O for the process
WBYTES - Bytes of write(2) I/O for the process
CNCLWB - Bytes of cancelled write(2) I/O
IO_READ_RATE - The I/O rate of read(2) in bytes per second for the process
IO_WRITE_RATE - The I/O rate of write(2) in bytes per second for the process
IO_RATE - Total I/O rate in bytes per second
CGROUP - Which cgroup the process is in
OOM - OOM (Out-of-Memory) killer score
IO_PRIORITY - I/O priority
M_PSS - proportional set size, same as M_RESIDENT but each page is divided by the number of processes sharing it
M_SWAP - Size of the process's swapped pages
M_PSSWP - shows proportional swap share of this mapping, unlike "Swap", this does not take into account swapped out page of underlying shmem objects
CTXT - Context switches (incremental sum of voluntary_ctxt_switches and nonvoluntary_ctxt_switches)
SECATTR - Security attribute of the process (e.g. SELinux or AppArmor)
COMM - comm string of the process from /proc/[pid]/comm
EXE - Basename of exe of the process from /proc/[pid]/exe
CWD - The current working directory of the process
AUTOGROUP_ID - The autogroup identifier of the process
AUTOGROUP_NICE - Nice value (the higher the value, the more other processes take priority) associated with the process autogroup
CCGROUP - Which cgroup the process is in (condensed to essentials)What I'm extremely interest in is:
IO_READ_RATE
IO_WRITE_RATE
RBYTES
WBYTES
IO_PRIORITY