Power consumption, HDD vs. SSD

I have been looking aroun the internet and found no anwsers so far. My question is:

Can anybody actually quantify the power consumption of the average SSD versus the average HDD (7200rpm sata)? An anwser in watts would be very useful as I am currently looking to see if I have the wattage headroom to upgrade graphics card and whether or not an upgrade to an SSD will allow for more wattage headroom.

Acording to the specs in seagate and samsung's sites.  A mechanical 3.5" HDD uses 8 Watts, while a SSD uses 3.5 watts.

Well without having done any research on this topic, it would only seem logical that an ssd wouldnt use anywhere need as much power because it has not heavy motors or electromagnets to power. 

An ssd relies on flash, which is a technology that doesnt rquire much power to run efficently

i allready knew that the HDD would consume more, the way in which technologies read and write data differently and how they work, but do you have a quantitative figure in watts?

5 watts difference isn't really gonna give any useful amount of headroom

It won't make that much difference. The only place where it would particularly matter is with laptops where battery life is at stake. With a laptop you can expect something like 45 minutes to an hour more battery life on notebooks that already get more than 5 hours of battery life. This is for the simple fact that either drive spends their expected amount of wattage when reading or writing data, regardless of how much is being written or read, all that really matters is how long the transfer takes. In the case of an SSD, not only to they require less power to begin with, but they also happen to perform transfers faster as well. But the difference will NOT give you headroom for things like graphics card upgrades if you have already maxed out your power supply.