Different Types of RAM

johndelgado · 2016-10-29T13:04:57.000Z

I was looking at buying some RAM for a Dell PowerEdge 710 and was wondering what the differences between PC3-10600, PC3-10600R, PC3-10600H, and PC3L-10600R are…

Assuming they’re all Registered ECC, would they all be compatible? I’ve tried searching to find the differences but Google doesn’t seem to like minor differences in strings.

peter · 2016-10-29T13:24:56.000Z

Crucial

Dell | Memory & SSD Upgrades | Crucial UK

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you can compare the different memory here, doesnt look like much difference but i would where possible stick with all memory the same

Rod-IT · 2016-10-29T13:25:00.000Z

No symbol is what most home PCs use

B - Buffered / Fully buffered

E - ECC registered

H - HyperCloud

LR - Load Reduced

P - Parity

R - Registered

U - Unbuffered

You also have single sided, dual sided, single, dual, triple and quad channel, single and dual ranked - it gets confusing - look at what is already installed and buy the same if you want to be sure

The L when in the middle (and not at the end) means Low Voltage, you need to ensure your board can take these

paolo0111 · 2016-10-29T14:24:54.000Z

Rod-IT:

look at what is already installed and buy the same if you want to be sure

Maybe you’re referring to the R710?

Dell

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The counsel of Rod-IT hits the mark, if you do not want to follow directions and models proposed by Dell itself.
In any case, welcome among us, dear johndelgado.

Robert5205 · 2016-10-29T15:41:07.000Z

If by “compatible” you mean “interchangeable,” then no.

RAM is made differently for different purposes. High-voltage RAM can be faster because a higher voltage lets you charge/discharge each memory cell more quickly. But higher voltage means more power means more heat. So, there is low-voltage RAM that uses less power. Not relevant for one server, but maybe for a farm of 1,000 or 10,000?

ECC is error-correcting RAM. Like a RAID disk array, it includes extra storage capacity that duplicates some of the stored information in a way that it can be re-created if an error is detected. Parity RAM, for example, can detect an error (and halt); ECC RAM can actually correct some errors and allow you to continue running.

Registered memory doesn’t mean it’s “registered” like signing in to a hotel. It means it has a “register” added to it. A register is a buffer that can hold a value that’s going to be read/written to memory. Instead of writing to the actual memory chip (and having to deal with accessing the chip, waiting for the bus to be free, synchronizing, etc.), you just dump the value to the chip’s buffer and tell it (memory controller) to complete the action when it can. It’s a way of offloading memory management from the CPU, which is busy doing more important things.

You want to use the memory that your system was designed for and for the application you want. In an HP ProLiant, for example, you can use different memory types and get different maximum bus speeds. Even how the DIMMs are placed in the slots will affect how fast they can be accessed.

johndelgado · 2016-10-29T21:23:16.000Z

Thanks for the wonderful responses… This is regarding a new system I’m building out, so I don’t have other modules to match against.

The reason for my question is that I have 2x 16GB DDR3 PC3-10600H (HyperCloud) ECC RDIMMs not noticing the H suffix so I’m curious as to rather or not it will work in a Dell PowerEdge R710?

Also, what’s the difference between buffered and registered? I was under the impression that they were the same…

pbp · 2016-10-30T02:35:04.000Z

Couldn’t find a great article putting all this together. NewEgg has a page leaning in the appropriate direction—

http://www.newegg.com/product/CategoryIntelligenceArticle.aspx?articleId=126#topic3
Higher level, http://www.newegg.com/Product/CategoryIntelligence.aspx?SubCategory=147
Could be a server memory page in there somewhere

Rod-IT · 2016-10-30T10:07:14.000Z

Usually when building a server you specify at least some ram with it (many actually come with a default amount as they are useless without it), when doing so the seller will match the ram type for you, you just specify an amount, if you are buying second hand or as a bare system, you may want to look at the spec of a pre-built system and make note of the memory they use, and go with that.

Since we don’t know if this is used, new, for production or lab it’s harder to assist, if the device is new and production, buy it with the ram, if this is used and for a lab, also buy it with ram, most second hand systems come populated with a lot of ram specifically for labs.

It’s only when adding more should you worry, if for some reason the system doesn’t come with any, including a default amount, I’d buy it from elsewhere. You wouldn’t buy a car without seats, don’t buy a server without ram either.

johndelgado · 2016-10-30T11:14:08.000Z

The parts are being bought individually, mostly used parts, through Ebay for home use and educational purposes. Hence why I’m trying to understand what HyperCloud RAM is and how you know if it’ll work in a motherboard. I can look up the spec sheet, I just don’t know what, specifically, I’m looking for on it.

Rod-IT · 2016-10-30T11:23:20.000Z

I would worry even less about the type and spec of the ram for a lab than the amount, you can buy used servers with 32GB plus installed in them for not a lot, why try to save money by buying the pieces separately, buy a used system that has been tested and works with the memory already installed.

Robert5205 · 2016-10-30T11:36:18.000Z

johndelgado:

The parts are being bought individually, mostly used parts, through Ebay for home use and educational purposes. Hence why I’m trying to understand what HyperCloud RAM is and how you know if it’ll work in a motherboard. I can look up the spec sheet, I just don’t know what, specifically, I’m looking for on it.

“Hypercloud” RAM (what an unfortunate name) is basically RAM with a built-in memory controller. The DIMM architecture is so complex that an external memory controller wouldn’t understand it. (Select memory bus x, channel y, rank z, etc.) So, they build some translation logic into the DIMM itself. Think of it as (roughly) the equivalent of LBA on a disk drive.

Unless you’re putting in some huge memory sticks, you shouldn’t run into it. But, if the RAM manufacturer says it would be compatible, then you have to take their word for it.

A system board is spec’d for certain types and amounts of RAM in a certain place on the bus. The memory controller detects this and adjusts bus speed and timing to match. If you add a second controller (on the DIMM) that spoofs the memory manager, that may increase memory density (but not capacity) at the cost of speed.

johndelgado · 2016-10-30T11:48:12.000Z

@Rod-IT, because part of the educational process is learning more about the hardware components and spec’ing them out too. There is no reason to buy more RAM if the RAM modules I already have will work. Also, from what I’ve seen in browsing ebay the past few days, it can be cheaper to buy the parts individually if you find older parts that larger data centers are replacing.

@Robert5205, thanks for the explanation - it kinda puts things into perspective. I’ve not seen any boards that explicitly say they work with HyperCloud RAM, so I’m at a bit of a loss on how to know if the board supports it or not.

Rod-IT · 2016-10-30T12:00:15.000Z

johndelgado:

I’ve not seen any boards that explicitly say they work with HyperCloud RAM

If it doesn’t say it supports it, it probably doesn’t.

Your also building a lab and are unlikely to see any benefit from it, your not a large enterprise and unless you are running huge memory chomping applications would probably never know if it existed or not.

It may also be listed by some companies as smart memory

A snip taken from the web

Netlist’s HCDIMM technology enables 384GB memory support at 1333MT/s in the latest generation Intel Xeon Processor E5-2600 server platforms, improving performance in business-critical applications as compared to industry-standard RDIMM or LRDIMM for large memory capacities.

Rod-IT · 2016-10-30T12:08:54.000Z

johndelgado:

@Rod-IT, because part of the educational process is learning more about the hardware components and spec’ing them out too. There is no reason to buy more RAM if the RAM modules I already have will work. Also, from what I’ve seen in browsing ebay the past few days, it can be cheaper to buy the parts individually if you find older parts that larger data centers are replacing…

I’m not disagreeing, sure this is part of the learning curve, but if you buy the wrong type and the supplier doesn’t accept returns or some of it is faulty and untested, you could end up spending again, meaning in the long run it costs you more.

Your best point of call is the manual for that model, how many CPU is installed also dictates how many and what size modules you can use

www.dell.com/downloads/global/…/en/server-poweredge-r710-tech-guidebook.pdf

Supported modules are listed as :- PC3-10600 DDR3 SDRAM DIMM 240-pin Advanced ECC Registered

johndelgado · 2016-10-30T13:44:52.000Z

Yea, unfortunately I’m well aware about the possibility of buying the wrong thing… I’ve made that mistake before, but I just relist the item and hope that it sells so I can get most of my money back. But that’s also why I do, literally, days worth of research and post questions on forums. That fear of making a wrong purchase is what leads me to asking the important questions that help me form a better understand and gives me the ability to make the necessary decisions.

I appreciate your concern and forewarning and I do realize that for something small like this, knowing all of the details isn’t a necessity. However, I do web development and I feel like having a strong understanding of servers and networking infrastructure will compliment that skill set as well as allow me to improve my own workflow and home IT administration.

As for the R710 specs, I’m just not sure if it would specify HyperCloud specifically and if it doesn’t, how one would determine if it works or not… From what I’ve read online, I’m leaning towards the idea that Dell doesn’t support HC RAM. Based on my understanding, there is only a single vendor that manufactures it. The only vendor I’ve noticed that has mentioned it is HP and they either rebrand it or have their own proprietary version of it called HPE or HP SmartMemory.

For instance, NetList states that “HyperCloud memory is available with the OEM model SYS-6026TT-BTF-GS015 12-slot” but the spec sheet makes no mention of it…

Rod-IT · 2016-10-30T14:17:14.000Z

As you noticed HP are the only one I could find also, if you don’t see it clearly mentioned, don’t worry about it, as I mentioned above unless you are installing huge amounts of ram, you likely wont notice anyway.

It’s a lab, your most important thing is amount, get as much as you can for as cheap as possible, you don’t need to worry if its ECC, low voltage, single, dual, triple or quad channel, pay more attention to how much you can get and the fact it is suitable for your device.

If you was looking to spec a server with 2TB of ram for mission critical data, I could see a reason to have concern about the type more.

I also understand learning is part of this, but don’t get too fixed on knowing it at this stage, your unlikely to need any speciality types at this point

johndelgado · 2016-10-30T14:28:42.000Z

Well the reason I’m fixed on knowing it is because I have 32GB of it and don’t wish to buy more unless it won’t work. In which case I’ll probably sell it and use that money to buy the RAM.

Also, while this is initially an educational experience, I do plan to build it out into a a FreeNAS box using either RAID-Z2 or mirrored drives and backup the 5 computers we have in the house into it, so I’m trying to pick a middle ground between the expensive stuff and parts that are so dated they’re impractical.

Anyway, we’re a bit off topic here… Thanks to all of you for sharing your comments, knowledge, and experience! It’s helped immensely!

Rod-IT · 2016-10-30T15:26:35.000Z

Going back to the HyperCloud modules, I see nothing to say Dell support these at all.

A couple of good reads though - scroll down on the first one, there is a response from the company direct, while an old post, it explains when and why you would use/benefit from this.

Note that this memory needs to be verified by the vendor HP, Dell, IBM etc. and is not validated by Intel or AMD like other memory)

DeinosCloud – 20 Jul 11

DIMMs And The Intel Nehalem Memory Architecture Connection

In this post I want to focus only on the intrinsic connection that exists between DIMMs and the Intel Nehalem regarding primarily the memory architecture. I was reading some good papers on this top…

HCDIMMs are viable but somewhat expensive alternative in the high capacity memory market if your server supports them. Netlist has been quite successful in convincing the server vendors: several models of HP, Supermicro, and Gigabyte support HCDIMMs. HP offers HCDIMMs in their most popular servers (DL380/DL360), although HCDIMMs can only be installed by HP.
About half way down
http://www.anandtech.com/show/6068/lrdimms-rdimms-supermicros-latest-twin/3