I have very slow transfer of data ( about thirty seconds) from my Magento 1.9. backend to the Sagpay payment gateway. Any thoughts anyone?
Are you noticing low bandwidth elsewhere or is it just SagePay? As far as I am aware there are no other reports so this leads me to believe your issue is related to your host limiting you.
If you could test something else, such as downloading a (large) file on the physical server, this would give a better idea.