This is my site 7 months graph from Google Webmaster Tools site performance util.

As you can see the graph goes up and down, with big differences: less than 1 second up to 5 sec.

Since I never changed anything (not an image, nor a script, nothing of nothing) during all those months do you think this could be caused by poor hosting, basically an overloaded server?

Are you experiencing the same up/down graph for some/all of your sites on Google Webmaster Tools?

BTW : ths site was also optimized with YSLOW, but optimized or not, shouldn't the graph be still more stright?

This is my site 7 months graph from Google Webmaster Tools site performance util.

As you can see the graph goes up and down, with big differences: less than 1 second up to 5 sec.

Since I never changed anything (not an image, nor a script, nothing of nothing) during all those months do you think this could be caused by poor hosting, basically an overloaded server?

Are you experiencing the same up/down graph for some/all of your sites on Google Webmaster Tools?

BTW : ths site was also optimized with YSLOW, but optimized or not, shouldn't the graph be still more stright?

EDIT: in Google Official Blog they show a pretty stright graph, but maybe it's just for graphic purpose.

This is my site graph from Google Webmaster Tools site performance util.

As you can see the graph goes up and down, with big differences: less than 1 second up to 5 sec.

Since I never changed anything (not an image, nor a script, nothing of nothing) during all those months do you think this could be caused by poor hosting, basically an overloaded server?

Are you experiencing the same up/down graph for some/all of your sites on Google Webmaster Tools?

BTW : ths site was also optimized with YSLOW, but optimized or not, shouldn't be the graph more stright?

This is my site 7 months graph from Google Webmaster Tools site performance util.

As you can see the graph goes up and down, with big differences: less than 1 second up to 5 sec.

Since I never changed anything (not an image, nor a script, nothing of nothing) during all those months do you think this could be caused by poor hosting, basically an overloaded server?

Are you experiencing the same up/down graph for some/all of your sites on Google Webmaster Tools?

BTW : ths site was also optimized with YSLOW, but optimized or not, shouldn't the graph be still more stright?