Performance implications using: XVFB, VNC, a Graphics Card

[Yogeeraj_1]

Hi experts,

I need to find a way in which i can compare the performance of my system when using XVFB against VNC or the graphics card installed on my system.

In fact, i have an application (Oracle Reports) which needs a X session for it to work (I need to include command: export DISPLAY=hostname:xx.0 in my startup script).

I have alternatives to use:
a. VNC,
b. XVFB
c. Creating an X session by connecting a monitor to my graphics card, launch an CDE X-session and finally run "xhost +"

I have already tested each of them - working fine!

Which option will give me the best performance on a heavily loaded system? why?

Thank you in advance for your replies and sharing your experiences.

Best Regards
Yogeeraj

[Alex Glennie]

best I can come up with is comapre the 3 options using glance : trial version available on applications CD's in conjunction with the general performance doc attached ?

also consider which products are supported by HP ... both xvfb and a native xserver are , VNC is not.

Personally I suspect the over heads for all 3 methods will be similar ....

[Yogeeraj_1]

Dear Mr. Glennie,

Thank you for the reply.

I did search this whole site before posting this question.

There have been some contradictory posts - (unfortunately i did not note down the urls)
A.

While Xvfb can be used if there is no video card in a system, it is not a recommended setup. In busy environments performance will suffer when using Xvfb. Try to get a video card for the system. ATI has Sun compatible cards that do not cost thousands of dollars.



Xvfb has only been required in headless systems. In trials by HP engineering, systems with Virtual Frame Buffers have seen some slower performance generating reports, but if the system is using your :0.0 display for generating graphics this may not be an issue.


My system already has a graphics card and CDE is working fine. Unfortunately, i have not been able to "automate" the process of creating an X session. Our production system runs 24x7 and power-cuts can bring our system down in the middle of the night and then to start the x session, we need someone to come manually create/start it!

About the comparison using Glance: How do i proceed? What should i look for?

Best Regards
Yogeeraj