I searched but not sure about solution:

I am going to upgrade a Dual xeon motherboard from a pair 2.0Ghz (Woodcrest 5130 dual cores) to a pair of 3.0ghz Harpertown X5365 Quad cores. Or maybe stick with just a dual core 3ghz (5160)?

However, I am not sure about "engineering" samples versus retail. Should I avoid the cheaper engineering sample (LGA 771- QWTH) and spend more on a retail CPU? What is the difference? (other than retail usually having a heatsink/fan) Is it worth the 50% savings?

TIA.

retail will also have a warranty which is aplus if you take into account the $$$ you will be spending. Also srtictly speaking engineering sample are either not legitimate (you'll get ripped off) or they are stolen. Avoid them.

Thanks! I was hoping that "bad feeling" I got was just that: no warranty, and not legit. Thank you!

I'd go for a single X5365 and then see where you are with that.

If a retailer is selling a ES chip tell on them. Email Intel and let the know. They are not supposed to be sold period. Maybe you are confusing an ES chip with a OEM but if a retailer is selling ES's that is a big no-no. People on this forum have gotten replacement chips from intel after getting ES from retailers. And the replacemnt was one of there top chips.

^+1 for telling.

@OP: If it's not OEM mind linking? I really want to see if they are selling ES. Ebay doesn't count as a "E/retailer" btw.