Connecting 1394 to motherboard

Yes, thank you, but my question was where to connect it on the motherboard. Because the manual does not specify. Can I connect it to a USB slot?

It is not mandatory to plug it in. It's not necessary for the operation of your PC anyway. You don't have to connect everything that's offered to you ^^

Okay, thanks.
Another small question. I saw on a website that the CPU connection is made with an 8-pin cable, but I don't have one coming out of my power supply. What should I do? :/

What is the model of your power supply and your motherboard?

My motherboard is a P8Z77-V LX and my power supply is a FSP450-60EP 500W.

Yes, exactly. However, for the fans, one side of the plug is male and the other is female.

And on your first photo, it's the plug coming out of my power supply, but as I told you, on this cable (before reaching this plug), there are two SATA plugs. What are they for? :/

Because there are two types of power supply for hard drives. Before, it was with a Molex connector (the one with 4 round pins) that powered the hard drive, but now it's SATA that plays this role.

Looking at this image, you have the SATA connector that powers the hard drive (the one on the far right) and on the far left is the slot for the one with the 4 round pins if your power supply doesn't have the other. When you have multiple connectors on one power cable, they are actually adapters in case the device only has one or the other. I hope you understood my explanation ^^

Otherwise, for the fans, is the connector at the end male or female?

Oh yes, okay, thank you very much for your explanation :)
The fans end with a male connector on one side and a female connector on the other.

However, I think it is better to buy a new power supply unit, because mine is too small for the Antec Nine Hundred case, so I can only secure it with one screw, and it only provides me with two Molex cables, while I have 4 fans :/ What do you think?

There are double adapters (adapters that double the connectivity you're looking for) so you can have your 4 sockets as you wish. It's up to you, but if your PC is not used for gaming, your new power supply that I can recommend won't be very expensive.

His FSP450-60EP power supply is also 80+ Bronze certified. And a 500W would do the job. I don't know what you think about keeping his power supply and buying the intended connectors? It would still be cheaper in the end.

I found these splitters https://www.ldlc.com/fiche/PB00229142.html. The price is really cheap. I don't know what you think, if it's better to invest in a PSU in ATX format (which would then be the right size compared to my current PSU). However, I saw on the second link that there are only 3 Molex connectors, so I would still need to buy a splitter.

I hadn't thought about your power supply being held up by just one screw :/ That's a bit risky for an installation, and if it falls (I assume the power supply is at the top of the case?), it could cause some damage.

No, the power supply unit is actually at the bottom, so it's fine, but I think it would be better if it were properly secured :/

for its power supply, it's 450 watts at 87%
in peak, it's around 500 watts

GTX 570 = under 3D load = 372 watts
at the wall outlet, and with the power supply losses
http://wd.ch-img.com/1199377-consommation.png

70 watts of reserve, the margin is good
check the connections

but are its case fans powered by a Molex each???

OK, but I have one last question. My hard drive and DVD drive connect via SATA connectors. Is it possible to use the SATA connectors that are present on Molex cables even if the Molex connectors are connected to the fans?

Of course, you just need to check if the cables are long enough to connect both.

the SATA power connectors are made to

ok ok, thank you very much for your help. However, for space (and safety) reasons, it might be better for me to invest in a new power supply with all the cables already included instead of buying several adapters, additional cables, splitters, etc. Considering that my graphics card is quite large and placed in the middle of my case, which means I have very little space left to arrange all the cables to each component and to the motherboard. What do you think? Even though the option of cables is advantageous due to its price.

If you prefer, for safety reasons and if the budget is not an issue for you, it would be better to get a new one of good quality, yes.

Personally, I recommend a Corsair or Antec 500W minimum. Check the specifications of these last two, they list the number of Molex, etc. to help you choose what suits you ;)

^^ We found the same one then ^^
So with this one, there's no need to invest in other cables to connect everything, right?
And wouldn't it be better to pay a little more and have a power supply a bit higher than 500W??

Response further up ^^

the Lepa has what it takes
https://www.topachat.com/pages/detail2_cat_est_micro_puis_rubrique_est_w_ali_puis_ref_est_in10060942.html

1 x 24-pin ATX power supply with detachable 4-pin section ¦
1 x PCI Express 8-pin power supply with detachable 2-pin section ¦
4 x internal 4-pin power supply ¦ => Molex
1 x 8-pin + 12V power supply with detachable 4-pin section ¦
1 x PCI Express 6-pin power supply ¦
5 x 15-pin serial ATA power supply ¦ => SATA
1 x mini 4-pin power connector

Exactly, but I didn't know this power supply brand.

Thank you for your help! But I think I'm going to stick with the Corsair CX500 V2, I'm going to buy it on ldlc.com, delivery takes two days and I've never had a bad surprise ;)