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0
Posted September 9th, 2019 06:00
Depends on the CASE Size.
DDR2 PC2-6400 • CL=6 • Unbuffered • NON-ECC • DDR2-800 • 1.8V • 256Meg x 64 •
2 GIGS is max dimm size and 4 or 8 gigs is max ram depending on how many ram slots your machine has.
14539
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Posted September 9th, 2019 18:00
Hi,
Its a Mini Tower and it has 4 memory slots. So it has 2x 1GB RAM sticks right now and I would like to populate the 3rd and 4th slots with 2GB sticks. But I will try adding one first, so is it supported to have 2x 1GB and 1x 2GB sticks configuration? The existing memories are DDR2 PC-5300 by the way so I guess I have to get the same kind.
Thank You!
Logbi
14498
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Posted September 10th, 2019 18:00
14492
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Posted September 10th, 2019 18:00
Welcome to the Dell Community @Logbi
Memory
Type 533, 667, or 800 MHz DDR2 SDRAMNOTE: 2-GB 800-MHz memory modules are not supported.
Memory connectors 4
Memory modules supported 256-MB, 512-MB, 1-GB, or 2-GB non-ECC
Minimum memory dual-channel: 512 MB
single-channel: 256 MB
Maximum memory At 533 or 667 MHz: 8 GB
At 800 MHz: 4 GB
Dell™ OptiPlex™ 745 User's Guide:
Mini Tower Computer Specifications:
Best regards,
U2
14481
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Posted September 11th, 2019 02:00
Hi donm4599x,
Thank you so much for you help! This is exactly what Im trying to figure.
9560
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Posted October 7th, 2020 12:00
" NOTE: 2-GB 800-MHz memory modules are not supported "
i purchased 2gb 800mhz memory by using a memory configurator, and later found this note as i was searching for the size of the hdd bay ( is it 3.5" ?)
1. is there a bios setting so that i can manually set the timing to 667, or will spd switch it automatically to 800
2. using mixed memory modules drops the speed down to the lowest specification, so i can check to see if 667 modules are installed, and only populate one bank for 1+2+1+2 gb = 6 gb (instead of desired 8 gb)
is there a bios setting for timing ?
i don't have the desktop in front of me, so i won't be able to find out for another 2 weeks
should i go ahead and exchange the memory modules now instead of experimenting
note: they say to not post questions in the answer section, but it's about the same optiplex 745, so i am hoping someone here may know the answer opposed to posting it on the forum
9542
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Posted October 7th, 2020 19:00
RAM speed cannot be changed in BIOS.
3239
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Posted October 8th, 2020 13:00
thank you for that. i'm left wondering how do you know. do you own an optiplex 745 ? is memory timing not configurable (vs cpu timing) ? can you give me some insight into your answer
1771
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Posted October 8th, 2020 13:00
1. Experience with BIOS. Optiplex's 755, 790, 7010.
2. Only one thing changes RAM speed. If you put 2 sticks 800MHz in your 745, then a stick with 667MHz, the system will operate all the RAM at 667MHz.
3. Over 2 years experience on this forum.
4. Over 100 total manuals, tech guides, spec sheets, & etc. downloaded for various Dell's. All of those things can be Googled. I download those from Dell only. So I pay attention to Google's links or download from Dell site.
There isn't a Tech Guide for the 745 that I could find. Below is a screengrab of what I do have on it:
donm4599x
2 Intern
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478 Posts
14533
1
Posted September 9th, 2019 19:00
2x 1GB and 1x 2GB should work fine, also adding both new 2GB sticks at the same time should work. It will save you another trip inside the case later.
If the memory sockets are color coded (.eg. two white and two black), then it has dual channel. Be sure to put the 1G devices in one color sockets, and the 2G devices in the other color sockets. If you don't, it will still run, but very slightly slower (in some applications) since it won't be able to use dual channels.
Be sure they are pushed all the way in (on both ends of the memory card) and snap the latches on each side of the memory cards closed.
Getting exactly the same ram as it currently has (except 2GB version) is surely the safest bet, but you can almost always get away with mixing brands as long as the speed and timing specs are the same.
Many times, even different speeds can get along, because the memory contains a table of supported standard jedec timings for the bios to choose from. As long as both types have an overlapping timing common to both memories (and to the motherboard), the bios will use it. So, they will run at the lowest speed common to the two types of memory. I wouldn't get memory any slower than what's in it, but the next faster speed should be fine, if you run across a good deal.