3rd hard drive or replace hd

[lectrocrew]

Then I only have to attach the cable from the power source?  But when I look at my old hd's that are connected they both have the same power source passing through it and I don't see a third connection.

What make/model power supply do you have?

Looking at the mother board and where my other 2 hard drives are connected, there seems to be 2 more sata slots parallel to the 2 that are connected.

This suggest that the 2 hard drives you have now are SATA rather than IDE. If so, do the power cables for these existing hard drives use SATA outputs from the PSU    or    do they use 4 pin molex-to-SATA adapter cables as shown in the picture Computer_Commando posted?

[washingmachine]

power supply- Rosewill RP500-2

The sata power outlets come straight from the Rosewill PSU, not the 4 pin molex-to-SATA adapter cables as shown in the picture Computer_Commando posted.  I was hoping I could get a 4 pin molex-to-sata adapter to power my 3rd hard drive?

[Computer_Commando]

...
pc specs
Intel core 2 duo e6300, ddr2 2048 mbytes, GeForce 8400gs...

This + 3 hard drives might push you over the limit for this psu.

http://educations.newegg.com/tool/psucalc/index.html

[lectrocrew]

power supply- Rosewill RP500-2

The sata power outlets come straight from the Rosewill PSU, not the 4 pin molex-to-SATA adapter cables as shown in the picture Computer_Commando posted.  I was hoping I could get a 4 pin molex-to-sata adapter to power my 3rd hard drive?

I see your situation now. Your PSU only has 2 SATA power outputs. Some PSU's have several (my Corsair TX850 has 8 SATA).
So yes you will need the adapter to run another SATA drive.
But as Computer_Commando pointed out, 3 hard drives may be pushing the limits on your PSU - I don't know, but you can do some math with a chart like this based on all the components on your machine.

[lectrocrew]

based on all the components on your machine.

IMO,  A good tool to use to find out exactly what hardware you have is Everest Free Edition which you can download here.

[washingmachine]

Thank you everyone for the information.  I now see that I can connect the adapter power supply for the hd but it could be too much wattage for the rosewill to handle.  So this leads me to 2 more questions before I put the 3rd hd in.  1) Can I disconnect the dvd/cd drive since I don't use it anymore?  2) If I decide to connect the 3rd hd because I am confident that my total wattage output will still be able to support my 3rd hd if I am wrong will it crash the whole system or will I need to just buy a larger power supply? (I feel it might be wiser to disconnect the dvd/cd player since I never use it.)  I appreciate all the help and wise advise everyone.

[lectrocrew]

Can I disconnect the dvd/cd drive since I don't use it anymore?

Yes, although it would not draw any current until a dvd/cd is inserted into it anyway.

2)  if I am wrong will it crash the whole system or will I need to just buy a larger power supply?

 It will not crash but it may not boot.
I googled what system hardware I do know you have and I beleive you'll be ok running the 3 hd's and keep the dvd/cd also.

One thing I'd suggest is to make sure the PSU fan and cooling grid is cleaned well with compressed-air-in-a-can available at most electronics stores or Walmart.

[truenorth]

I would proceed with your installation to determine if there is a PSU problem before expending any additional money to upgrade the PSU. Then should you find that the required additional power is required i would suggest this as an alternative to a greater capacity PSU.
http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=4143852&csid=_21
It will be far less costly and will allow you to continue using your current otherwise functioning PSU. It will also provide great versatility to your HDD options for using your current drive you want to use as well as others. It has it's own power supply unit. truenorth

[lectrocrew]

I would proceed with your installation to determine if there is a PSU problem before expending any additional money to upgrade the PSU. Then should you find that the required additional power is required i would suggest this as an alternative to a greater capacity PSU.

Agreed!

http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=4143852&csid=_21

Thanks Truenorth! I like that hardware, especially considering I bought this USB HD enclosure
last February for $29.99, and it has no card reader nor USB hub. I may get one of those Ultra ULT40326 Hard Drive Dock's for myself real soon. 

[washingmachine]

Cool, thanks truenorth, it looks like an external internal hd.  I'm putting the hd in now but if it doesn't work because of PSU sortage issues I will definitely look into the gizmo you posted.

[washingmachine]

Sweets, all systems go.  Thank you again everyone for your knowledge and help.  (now its time to start filling up that hd)

[truenorth]

washingmachine, Well done,congrats,truenorth

[lectrocrew]

Sweets, all systems go. 

Excellent! Glad you got it going washingmachine. 

[soybean]

http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=4143852&csid=_21

I noticed that TigerDirect says this item is only available in stores.  I presume they mean CompUSA stores, which now only exist a few cities in the U.S.  So, how did you get it?  Do you live near one of those stores?

[truenorth]

soybean, It was a recommendation NOT based on personal ownership. I became aware of this type of devise not long ago (posted a reference at the time on another CH forum) and did more research to view similar products and the one i posted in this thread came up and i thought it would suit the O/P in this instance if inadequate power was available for his HDD installation. I have shopped at a bricks and mortar Tiger Direct near Atalanta GA (but it is 1200 miles away--so certainly not close). Apparently there is one in Toronto Ontario Canada --but that one is still about 450 miles away. I would be very surprised that it is NOT available as an online purchase. Can you phone them to see? If not PM me and I'll do it for you (plus any other questions you may have about it).truenorth