Can someone remind me how noisy ISO 400 really is

I am into using old film at the moment, and scanning, I must admit I have not used a 35mm ISO 400 film for many years, and forget how noisy it is expected to be, the ones I am getting processed after scanning seem to be really really noisy, even the first film that was scanned by Tescos was really noisy, and my scans are less noisy, it is not really bothering me, except I need a bench mark.
I know there are a lot of variables, but just would like an idea off anyone who has shot a lot of ISO film

Also is there any hardware about that is quick and easy to view negs, to see more what the actual neg looks like

Can the processing of the film effect the amount of noise that would end up on the neg?

Thanks
Thanks

Brett, I cannot answer the first part as I have not scanned my ISO400 negatives or photos just yet but I have seen acceptable levels of noise on 6x4 prints even up to 1600 so far so will leave that for someone who has shot more film.

As for the scanning, I use a Canoscan lide 80 which comes with a negative scanner module/plate to scan in negatives easier.

Thanks Mitesh, maybe I am expecting too much, as thinking about it as you said in a 6 x 4 prints it is acceptable, but of course I am scanning at 4000 DPI, and the images are massive to to zoom in you are going to get a load of noise.

More experiments needed and testing

MaDProFF wrote in post #6156387
Can the processing of the film effect the amount of noise that would end up on the neg?

Definitly. Overdevelopment, caused by either too warm developer or too much time in the soup, will increase grain. The choice of developer can be a factor also.