Side Question:
If anyone knows any cheap/reasonably priced alternatives for upgrading a 1gbps network to anything faster, let me know!
Main Question:
I’ve been looking at SFP+ DAC and the SR Transceiver Modules.
Since it’s a plug you slot into the PCI-E card are you able to use a SFP+ DAC in place of the SR Transceiver Module?
The plugs seem pretty much identical as far as I can tell, that doesn’t mean it will work however.
I’ve not been able to find any websites to cover my question unfortunately.
Blasted 1Gbps network, if only 10Gbps wasn’t so expensive!
SR Transceiver: (Copy and paste the link, couldn’t get it not to preview 
)
puu.sh/k7GMN/b9b687a1d4.jpg
SFP+ DAC:
puu.sh/k7GNt/ed284614f0.jpg
Yes I believe so. DAC cables are used to connect one sfp slot to another without the need for a transceiver, but I'm not sure if there is some proprietary nonsense that would prevent different brands from working with each other.
I have a 10gb link between two computers using older 10gb cards with xfp modules. I managed to get two of them on ebay for $100. Might be worth having a look. The only trouble I had was one of then (netxen I think) didn't work with the version of Linux I was using without upgrading the firmware which was a hassle. If you're using Windows I'm not sure how you will go with drivers for older server cards.
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Hey thanks! I've done a bit more digging and I think you're right, I've read up a few different switching that will support either DAC or optical! So hopefully it's the same for the cards.
In general, you can use an sfp or sfp+ port with a cable or transceiver. A passive cable shouldn't have any compatibility problems, I've seen some active cables not work correctly across different vendors. With transceivers, there shouldn't be compatibility issues but once again it comes down to the vendor and if they have the device check to verify the PN of the module. I usually get cheap connectx-2 10gbe cards that are HP branded and then flash them to stock Mellanox firmware. You can do the same with connectx-3 cards but they cost about twice as much more. You have to look at the features you gain on if they are worth.
If you list the hardware you have or are looking at, what you plan to do with it, and how far the connections are, I could tell you more.
In general though, It is better to go with DAC if within the same rack and you will be moving it around more, and fiber if it is greater distance and moved around less. This is mainly due to the cost of copper and the cables getting ridiculously priced as they get longer. If you go DAC, get a passive cable from ebay and if you go fiber go to fiberstore and get some transceivers. The SFP-10G85-3M is a generic module that supports 300 meter MM 50/125um LC and is only $16 each.