SATA/300 or 3.0Gbps is compatible with SATA/150 or 1.5Gbps; it works the same there is little difference except the speed. Note however no harddrive exists that really gets any speed benefit from using 3.0Gbps, since harddrives cannot achieve 150MB/s yet.
So if you get SATA/300, the cable can transfer up to 300MB/s, but the drive itself will still be limited to 50 - 125MB/s. If you're doing this for speed, don't have any expectations that SATA/300 will be any faster.
im doing this because the hard drive im considering buying to replace the pos Seagate thats writing at 1.5-3mb/sec is a sata 300 drive, and i need to boot a floppy to switch it over to 1.5 and i cant do that unless i have the controller. here ill post the links
If your harddrive only transfers under 5MB/s, you probably have a PIO issue. This is very common and has 20 million hits on Google. You can fix it pretty easy and the drive should run faster.
Please download HDTune from the web, run a benchmark on the drive, let it finish, make a screenshot and post it here. I should be able to tell whether or not you have a PIO issue. If you do, you can resolve it with just a few mouse clicks and your drive will run at full speed again.
PIO is unrelated to what controller you use, and its likely not the fault of the HDD. Any harddrive or SSD can have a PIO problem; its a design weakness in Windows. PIO is a 'fail safe' mode that's used as fallback solution whenever a DMA transfer fails. DMA is what you should be using - Direct Memory Access. PIO will always be slow and comes with very high CPU (interrupt) usage causing extremely slow performance, sometimes even slowing your mouse down.
In most cases, deleting/uninstalling the SATA controller in Device Manager will fix the problem. After rebooting, it will automatically find and install the controller again and this will 'reset' the transfer mode to DMA like it should be and the speed problems and high CPU usage should be fixed.
If not, it may be a cable issue. Bad cables can cause PIO problems. Especially if after resetting to DMA it falls back to PIO again after some minutes, its likely a cable issue - replace the cable with a GOOD quality cable and do not bend the cable but let it go naturally in your computer casing.
In device manager, do not delete the drive itself, but the controller it is connected to. For example a screenshot:
The controller which says PIO, which is, if you did the red arrows correctly, "Secondary IDE channel".
It can't really hurt to delete/uninstall them; you can remove all of them and they will be found next time you boot. Check the tabs again to see if it still says PIO or says DMA. It should say DMA. Then test with HDTune to see if your speeds and CPU usage return to normal.
You have 2 pending bad sectors. And the drive is extremely hot which would limit its lifespan. Make sure the drive is properly cooled, backup all data and overwrite the drive with zeroes using a zero-write utility. This will make the "uncorrectable pending sectors" disappear and convert into "reallocated sectors". Currently you have 3 bad sectors which have been replaced by reserve sectors and 2 bad sectors which cannot be replaced until you write to those sectors; that's why you need a zero-write.
The seek error rate is also very high, but that might be related to your extremely high temperature. Generally you should treat your drives better; as they are vulnerable mechanical devices prone to failure. Do not store anything valuable on the drive unless you got a good backup.
i have a older drive which has probably taken far more of a beating than the one i showed and also i believe that one drive fails to record temperatures right, ether way there isnt much i can do about keeping them colder, and the high seek rate, i believe that is something that seagates fail to report accurately, i looked up seagate and it told me that in the smart for it there are a few values that will be way off and that is just normal for a seagate. the other drive is 4 years old and it doesn't have a single error on it and its been running during summer when my room can reach over 100f, the drives have to run a crap ton hotter than than now when my room stays sub 70 if i have any say in the matter.
can you explain that zero-write utility a bit. and what will happen when i use it?