Reduced RAM amount when using RAID?

pbmaster · Sep 9, 2009

I just got my RAID setup yesterday, and I noticed that several programs report 4086 MB of RAM. I know that it's not supposed to see exactly 4096 MB, but before I was using RAID it saw something like 4094 MB. Does running RAID reserve a small amount of RAM? I know 10 MB isn't that much, but I'd still like to know what's going on. Thanks!

newfellow · Sep 11, 2009

That's actually exact 8MB. Wonder what RAID controller are you using. I know Intel ICH9/10R nor NVIDIA nforce won't take RAM, but there could be something 'new' I haven't heard of.

Not exactly sure on AMD790/SB750 chipsets. Never had one, but good info, if so.

Kursah · Sep 11, 2009

Could be a detection glitch when Raid is active maybe? I've never noticed that, but I only tried raid for a few months, left dissapointed beyond benches for my uses. Maybe contact Asus and see what they have to say about it?

pbmaster · Sep 11, 2009

I'm not really concerned as long as more of my RAM doesn't start magically disappearing. My buddy who works at a local PC shop said it was something to do with the ATi card and Vista x64...not too sure other than that though.

Bundy · Sep 11, 2009

newfellow said:
That's actually exact 8MB. Wonder what RAID controller are you using. I know Intel ICH9/10R nor NVIDIA nforce won't take RAM, but there could be something 'new' I haven't heard of.

Not exactly sure on AMD790/SB750 chipsets. Never had one, but good info, if so.

How do you know that ICH9/10 don't take RAM? I'd be intersted to read.
As far as I understand, onboard RAID uses the CPU via drivers that are loaded prior to the OS. It might be possible the missing RAM is those drivers. IDK

Maban · Sep 11, 2009

I'm getting a few drives for Raid 5. Getting two Monday and the other will be Tuesday. If I remember and if it hasn't been explained I'll post my results.

pbmaster · Sep 11, 2009

I could be totally off on this, but it makes sense that some of the RAM could be reserved for the RAID drivers. And again, it's only 10 MB. I'd just like to know where it went.

phanbuey · Sep 11, 2009

hmmm I have raid and all me ram is there... but then again I have nvidia... Ive never heard of raid array taking ram and locking like a onboard gfx or something- sure the driver may use ram, but I doubt that it would make the ram totally invisible to applications. they should still detect all of it, even is some of it is used by the driver.

In short. I dunno... but RAID isn't supposed to take any ram and hide it from the system. But every controller works differently so IDK. Has the googles turned anything up similar with that MB?

Meow9000 · Sep 12, 2009

Write cache reliability
Some RAID systems use RAM write cache to increase performance. A power failure can result in data loss unless this sort of disk buffer is supplemented with a battery to ensure that the buffer has enough time to write from RAM back to disk.

Might answer your question

pbmaster · Sep 13, 2009

I understand that software RAID uses RAM along with CPU time, but what I'm trying to figure out is if it results in less total RAM reported. In every sort of diagnostic 4086 MB RAM is reported, instead of the 4094 MB that previously was.

phanbuey · Sep 13, 2009

if it is the only thing that changed, than chances are that it is the cause of ram being reported incorrectly. When software, even drivers, use RAM - very seldom is it hidden in a way that the system fails to report it to applications that ask for the total amount of ram. Even unavailable ram is usually reported in system diagnostics.

95Viper · Sep 13, 2009

I have 4094 total and 4096 installed. I have Intel Raid using two drives.

You don't by chance have any bios or other shadowing options in the bios set up turned on?

Maban · Sep 20, 2009

RAID 0 here and still 4094. Forgot to check when I tried 5.

Processor	AMD Phenom II 955
Motherboard	Asus Crosshair III Formula
Cooling	Cooler Master V8 CPU cooler, 120 mm and 200 mm exhaust, 3 x 120 mm intake
Memory	4 GB OCZ DDR3 1600
Video Card(s)	Sapphire Radeon HD 4890
Storage	Western Digital 500 GB Blacks in RAID 0/ Wesdtern Digital SE16 250 GB
Display(s)	Acer 19" widescreen
Case	Antec Nine Hundred
Audio Device(s)	Supreme X-Fi
Power Supply	Seasonic M12 SS-700HM
Software	Windows Vista Home Premium x64 SP2
Benchmark Scores	3dMark 03-~62k 3dMark 05-~22k 3dMark 06-18268

System Name	ID
Processor	Q9450 ~3.74Ghz
Motherboard	ASUS-P5E
Cooling	Air
Memory	G.Skill CL4-8GB
Video Card(s)	ATI/Geforce 5850/9800
Storage	A-lot
Display(s)	BenQ G2400WT
Case	900
Audio Device(s)	Shitty ASUS FX;P
Power Supply	OCZ GXS 850W
Software	-
Benchmark Scores	too many machines to spec

System Name	Kursah's Gaming Rig 2018 (2022 Upgrade) - Ryzen+ Edition \| Gaming Laptop (Lenovo Legion 5i Pro 2022)
Processor	R7 5800X @ Stock \| i7 12700H @ Stock
Motherboard	Asus ROG Strix X370-F Gaming BIOS 6203\| Legion 5i Pro NM-E231
Cooling	Noctua NH-U14S Push-Pull + NT-H1 \| Stock Cooling
Memory	TEAMGROUP T-Force Vulcan Z 32GB (2x16) DDR4 4000 @ 3600 18-20-20-42 1.35v \| 32GB DDR5 4800 (2x16)
Video Card(s)	Palit GeForce RTX 4070 JetStream 12GB \| CPU-based Intel Iris XE + RTX 3070 8GB 150W
Storage	4TB SP UD90 NVME, 960GB SATA SSD, 2TB HDD \| 1TB Samsung OEM NVME SSD + 4TB Crucial P3 Plus NVME SSD
Display(s)	Acer 28" 4K VG280K x2 \| 16" 2560x1600 built-in
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Audio Device(s)	Aune T1 mk1 > AKG K553 Pro + JVC HA-RX 700 (Equalizer APO + PeaceUI) \| Bluetooth Earbuds (BX29)
Power Supply	EVGA 750G2 Modular + APC Back-UPS Pro 1500 \| 300W OEM (heavy use) or Lenovo Legion C135W GAN (light)
Mouse	Logitech G502 \| Logitech M330
Keyboard	HyperX Alloy Core RGB \| Built in Keyboard (Lenovo laptop KB FTW)
Software	Windows 11 Pro x64 \| Windows 11 Home x64

Processor	AMD Phenom II 955
Motherboard	Asus Crosshair III Formula
Cooling	Cooler Master V8 CPU cooler, 120 mm and 200 mm exhaust, 3 x 120 mm intake
Memory	4 GB OCZ DDR3 1600
Video Card(s)	Sapphire Radeon HD 4890
Storage	Western Digital 500 GB Blacks in RAID 0/ Wesdtern Digital SE16 250 GB
Display(s)	Acer 19" widescreen
Case	Antec Nine Hundred
Audio Device(s)	Supreme X-Fi
Power Supply	Seasonic M12 SS-700HM
Software	Windows Vista Home Premium x64 SP2
Benchmark Scores	3dMark 03-~62k 3dMark 05-~22k 3dMark 06-18268

System Name	Grandpa
Processor	i5 4690K
Motherboard	Gigabyte Z97X-UD5H-BK
Cooling	water
Memory	8GB Corsair Vengence 2400MHz
Video Card(s)	Gigabyte 5850 x2
Storage	Samsung SM951
Display(s)	Catleap 27"
Case	coolermaster stacker
Power Supply	corsair AX860i
Mouse	logitech g5 original
Keyboard	Ducky
Software	Windows 8.1

Reduced RAM amount when using RAID?

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newfellow

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Maban

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Motherboard	MSI 690-I PRO
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Video Card(s)	RTX 4090 FE
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Case	SLIGER S620
Audio Device(s)	Yes
Power Supply	Corsair SF750
Mouse	Xlite V2
Keyboard	RoyalAxe
Software	Windows 11
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Processor	AMD PHENOM 9950BE x4 (140W)
Motherboard	ASUS CROSSHAIR II (BIOS 2003)
Cooling	ZALMAN 9700L
Memory	4GB CORSAIR DOMINATOR 1066 (2x2GB)
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Power Supply	OCZ 700W
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