Want 1.5TB of RAM in Your PC? It Will Cost You • Hacker News Board

Re: Want 1.5TB of RAM in Your PC? It Will Cost You

#51

Post by dingo_bat » Sun, Sep 08, 2019, 5:09 PM UTC

Wowfunhappy wrote: post #16

I decided to put 32 GB of Ram in my home desktop some months back. I knew I didn’t need that much, but I figured macOS (it’s a Hackintosh) would use it for file caching or some such. To my disappointment, it goes completely unused more often than not. According to Activity Monitor, I currently have around 7 gb just sitting idle.

In my experience windows utilizes ram much better. It will cache programs and data at times it anticipates you will use them. For example it will cache outlook at 9 am in the morning because that's the time I check my email.

At all times only a very small fraction of my ram is free.

Re: Want 1.5TB of RAM in Your PC? It Will Cost You

#52

Post by AstralStorm » Sun, Sep 08, 2019, 5:24 PM UTC

jdsully wrote: post #42

basch wrote: post #24

Earlier quoted context omitted.

with VROC or the Threadripper equivalent NVME CPU RAID, you can get 7Gbps read speed from a RAID5. Thats DDR2 speed. Unless you truly need DDR4 speeds, I would think you would be better off for your money using CPU Raid and NVME. More drives, more speed. One guy used 8 drives and got 28Gbps. https://i.imgur.com/AuCWq3r.jpg

Linear throughput is the wrong way to think about this. Random access is much more important for DRAM workloads. Persistent memory has a block size of 4 cache lines (256 bytes) vs 4KB for an SSD. This drastically cuts down on read/write amplification.

Generally burst access and not random is important. A few MB at a time.

Re: Want 1.5TB of RAM in Your PC? It Will Cost You

#53

Post by eesmith » Sun, Sep 08, 2019, 5:55 PM UTC

drewg123 wrote: post #13

fasteo wrote: post #2

I've done some shopping around, and the best pricing I can find puts these 128GB RAM at about $1,500. Each. Yes, each. Some back of the envelope math -- or math in your head if you are good at that sort of thing -- put the price of 1.5TB of RAM at a cool $18,000. If my memory serves me well, I routinely bought 1Mb RAM modules for 5.500 Spanish pesetas (33 Euro). This was around 1987-1990 I believe. If my math is righ…

In 1993, one of my first tasks in a new job as a sysadmin was to install 256MB of RAM into a DEC Alpha 3000/500. I remember the RAM cost on the order of $20k... I don't remember the exact price, but I remember thinking that the RAM was worth more than I was, and I'd better not screw it up.

graph of "Historical Cost of Computer Memory and Storage", https://jcmit.net/mem2015.htm . Memory data at https://jcmit.net/memoryprice.htm .

1994 prices are US$30.0/MB or $8K for 256MB of PC-grade memory. Looks like the DEC machine used 200-pin SIMMs, says https://www.memoryx.com/ms15da.html (listing 64MB for $200). Don't know how that compares.

BTW, $400 for a DEC Alpha 3000/500 at https://www.ebay.com/itm/DEC-DIGITAL-ALPHA-SERVER-3000-500-P... .

Re: Want 1.5TB of RAM in Your PC? It Will Cost You

#54

Post by turbo_fart_box » Sun, Sep 08, 2019, 6:17 PM UTC

segfaultbuserr wrote: post #32

std_throwaway wrote: post #8

Earlier quoted context omitted.

An Arduino UNO comes with 2 kB of RAM installed and retails for about 20$. If you want to get 1.5 TB of RAM by connecting them (not accounting for any overhead on each controller) you would need 800 Million Arudino UNOs which would cost you about 16 Billion Dollars.

> An Arduino UNO comes with 2 kB of RAM installed and retails for about 20$. This is not an accurate calculation, first, the main cost of an Arduino is its PCB and the supporting electronics, plus some profit margins to cover the overhead for the manufacturer. Also, the RAM is not "installed", the actual device where the 2 KiB RAM resides in, is etched on the same silicon chip of the Atmega328p microcontroller. A 328…

It's a joke.

Re: Want 1.5TB of RAM in Your PC? It Will Cost You

#55

Post by anarazel » Sun, Sep 08, 2019, 7:43 PM UTC

segmondy wrote: post #48

I just want to know why anyone will personally need 1.5TB of ram in their personal PC today. I'm not saying that 128gb is all we need. I'm sure in the future, we might all have 32TB in our future portal device. But what sort of work load or app could you possibly need 1.5TB of ram for? On my personal desktop right now. I have 20gb of ram and over 250tabs open on Firefox, spotify, VCode, Postgresql, pgadmin, multiple…

I would love it for development (I work from home on personal HW) - multi-socket NUMA machines behave differently enough that being able to continually see how in-development software versions behave. And I just find it less productive / more painful to do detailed performance work remotely. Latency is one part, added time due to having to sync up code / build another, but there's more that I can't really pinpoint.

Re: Want 1.5TB of RAM in Your PC? It Will Cost You

#56

Post by std_throwaway » Sun, Sep 08, 2019, 7:44 PM UTC

turbo_fart_box wrote: post #54

segfaultbuserr wrote: post #32

Earlier quoted context omitted.

> An Arduino UNO comes with 2 kB of RAM installed and retails for about 20$. This is not an accurate calculation, first, the main cost of an Arduino is its PCB and the supporting electronics, plus some profit margins to cover the overhead for the manufacturer. Also, the RAM is not "installed", the actual device where the 2 KiB RAM resides in, is etched on the same silicon chip of the Atmega328p microcontroller. A 328…

It's a joke.

I thought the topic was unreasonable comparisons. I was wrong; it was nostalgia.

I should have compared with magnet core memory used in the Apollo program as an example. My gut tells me that we don't have enough rocket fuel to install that kind of memory in space.

Re: Want 1.5TB of RAM in Your PC? It Will Cost You

#57

Post by std_throwaway » Sun, Sep 08, 2019, 7:53 PM UTC

segfaultbuserr wrote: post #32

std_throwaway wrote: post #8

Earlier quoted context omitted.

An Arduino UNO comes with 2 kB of RAM installed and retails for about 20$. If you want to get 1.5 TB of RAM by connecting them (not accounting for any overhead on each controller) you would need 800 Million Arudino UNOs which would cost you about 16 Billion Dollars.

> An Arduino UNO comes with 2 kB of RAM installed and retails for about 20$. This is not an accurate calculation, first, the main cost of an Arduino is its PCB and the supporting electronics, plus some profit margins to cover the overhead for the manufacturer. Also, the RAM is not "installed", the actual device where the 2 KiB RAM resides in, is etched on the same silicon chip of the Atmega328p microcontroller. A 328…

The memory sticks we're talking about here also come on a PCB, so we should not exclude that cost. What use would loose chips be if they are not soldered onto a PCB? You could argue that there could be a supplier that produces working memory sticks for a cheaper price. I'm not contending that. These products, however, are unfamiliar to most people and Arduino UNO is a brand name that many people recognize. There are many cheap knockoffs of that product that may or may not be compatible. I would prefer to stay with respected manufacturers in this case.

It is true that those micro controllers are bundled with the memory. In other words, the memory also has computing power installed. A capability that some modern memory chips also include. You may argue that we should compare with those memory chips, however, in the case of micro controllers we cannot separate the memory from the computing unit and we need the computing unit for communication. Is the comparison thus unfair? Maybe.

Re: Want 1.5TB of RAM in Your PC? It Will Cost You

#58

Post by basch » Sun, Sep 08, 2019, 9:28 PM UTC

termie wrote: post #33

basch wrote: post #24

Earlier quoted context omitted.

with VROC or the Threadripper equivalent NVME CPU RAID, you can get 7Gbps read speed from a RAID5. Thats DDR2 speed. Unless you truly need DDR4 speeds, I would think you would be better off for your money using CPU Raid and NVME. More drives, more speed. One guy used 8 drives and got 28Gbps. https://i.imgur.com/AuCWq3r.jpg

The throughput is amazing. The screenshot shows 28,375 MB/s — the capital B typically indicates Bytes whereas a lowercase b indicates bits, so your Gb/s translation is a little confusing. The latency is still much higher than main memory or Optane, but that might be fine for many applications.

youre right, I didnt look closely at the buttons, I just assumed bits based on the all caps used all over the interface.

Re: Want 1.5TB of RAM in Your PC? It Will Cost You

#59

Post by dis-sys » Mon, Sep 09, 2019, 1:25 AM UTC

jsjohnst wrote: post #34

dis-sys wrote: post #14

in case you don't have $18,000 to buy those fancy brand new DDR4 RAM - second hand 64GB DDR3 ECC REG RAM is about $100 each, a dual socket c602 motherboard such as my Z9PE-D16 has 16 memory slots, having 16 x 64GB = 1TB RAM in such a workstation costs you $1,600. bargain!

Does the Z9PE-D16 actually support 64gb DIMMs though? ASUS claims it only supports 32gb for a total of 512gb, but that could easily be because they didn’t update their marketing material rather than a technical limitation.

my understanding is that memory controllers are in the processors, motherboard just provide the slots, it shouldn't be a limiting factor to stop you using 64GB DIMMs.

Re: Want 1.5TB of RAM in Your PC? It Will Cost You

#60

Post by dis-sys » Mon, Sep 09, 2019, 1:25 AM UTC

fourcolordeck wrote: post #21

dis-sys wrote: post #14

in case you don't have $18,000 to buy those fancy brand new DDR4 RAM - second hand 64GB DDR3 ECC REG RAM is about $100 each, a dual socket c602 motherboard such as my Z9PE-D16 has 16 memory slots, having 16 x 64GB = 1TB RAM in such a workstation costs you $1,600. bargain!

Best place to pickup 2nd hand?

ebay.com taobao.com