As i noticed a discussion on RAM limit above, I would like to start one too, but about my board:
I have a HP Compaq t5500 Thin Client
http://h18002.www1.hp.com/products/quickspecs/11746_div/11746_div.HTML http://www.transmeta.com/success/thin/hp/hp_t5500.html http://www.transmeta.com/success/thin/hp/hp_t5500_spec.html
It has a TRANSMETA CRUSOE 5800A073310 CPU (TM5800) with integrated northbridge, and a VIA VT8231 southbridge.
29LV160ATTC-90 2 MB flash chip (soldered).
I would like to put LinuxBIOS on it, and I would like to put as much RAM as possible in it.
It has 1 SO-DIMM 200-pin DDR slot, and some place for soldering RAM chips on the board.
In the slot there is a 128 MB module now. HP specs say you can put max 512 MB module there.
What are the real RAM limits? The TM5800 CPU supports 4 GB of RAM, so thats the upper limit, but is there anything that limits it lower, and if so what?
I am now planning to buy a 1 GB DDR SO-DIMM module, and I hope it'll work in the slot. Will it? Will only some modules work? If so what should I look for? Will this module work: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6821167601
I found somewhere that: TM5800 memory subsystems can be populated with 64-Mbit (4M x 16 or 8M x 8), 128-Mbit (8M x 16 or 16M x 8), 256-Mbit (16M x 16 or 32M x 8), or 512-Mbit (32M x 16 or 64M x 8) devices. Note that only x8 and x16 memory devices are supported.
Does it mean that if only my module is made of 32Mx16 or 64Mx8 chips, it'll work? Or is there anything more required? Does the VIA VT8231 or the thing's BIOS creates any more limits? With LinuxBIOS will I be able to put more RAM in than with stock BIOS?
And finally is there anyone here who uses LinuxBIOS on such CPU and southbridge, and can share some expirience?
Miernik wrote:
What are the real RAM limits?
The "real" RAM size limit is a function of several aspects of the design.
Design of the memory controller silicon PCB layout Number of DIMM memory slots Design and layout of the actual DIMM's BIOS
The TM5800 CPU supports 4 GB of RAM, so
The TM5800 can directly address 4GB of memory space since it is a 32 bit cpu. However the maximum memory size in the DIMM sockets the TM5800 can address is 1025MB arranged as two banks of 512MB or four banks of 256MB.
What the maximum DRAM size is for the thin client design by HP depends on how they designed the PCB and BIOS.
thats the upper limit, but is there anything that limits it lower, and if so what?
Design of the memory controller silicon and available DIMM configurations plus BIOS sets the lower limit.
The memory controller can handle devices as small as 4M x 16 and with one bank. Its lower limit then is 32MB.
I am now planning to buy a 1 GB DDR SO-DIMM module, and I hope it'll work in the slot. Will it? Will only some modules work? If so what should I look for? Will this module work: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6821167601
I found somewhere that: TM5800 memory subsystems can be populated with 64-Mbit (4M x 16 or 8M x 8), 128-Mbit (8M x 16 or 16M x 8), 256-Mbit (16M x 16 or 32M x 8), or 512-Mbit (32M x 16 or 64M x 8) devices. Note that only x8 and x16 memory devices are supported.
Does it mean that if only my module is made of 32Mx16 or 64Mx8 chips, it'll work? Or is there anything more required? Does the VIA VT8231 or the thing's BIOS creates any more limits? With LinuxBIOS will I be able to put more RAM in than with stock BIOS?
And finally is there anyone here who uses LinuxBIOS on such CPU and southbridge, and can share some expirience?
Look for modules that that minimize the number of loads. Use the largest capacity devices possible for a given memory size. The SDRAM interface cannot drive more than sixteen unbuffered devices. SDR SDRAM configurations requiring more than sixteen loads must use buffered SDR memory.
-Bari
Bari Ari bari@onelabs.com wrote:
The TM5800 can directly address 4GB of memory space since it is a 32 bit cpu. However the maximum memory size in the DIMM sockets the TM5800 can address is 1025MB
1024 MB you mean?
If only 1 GB can go in DIMM sockets, where can the remaining 3 GB go?
arranged as two banks of 512MB or four banks of 256MB.
Is "bank" = "1 DIMM module" or?
Design of the memory controller silicon
Is the memory controller silicon inside the TM5800, or is it some separate chip?
Look for modules that that minimize the number of loads.
What are "loads"?
The SDRAM interface cannot drive more than sixteen unbuffered devices. SDR SDRAM configurations requiring more than sixteen loads must use buffered SDR memory.
But I am talking about DDR here, not SDR.
TM5800 does not support buffered memory: http://transmeta.com/crusoe_docs/TM5800v2.1_databook_030922.pdf Page 2, section 1.2.1
Miernik wrote:
Bari Ari bari@onelabs.com wrote:
The TM5800 can directly address 4GB of memory space since it is a 32 bit cpu. However the maximum memory size in the DIMM sockets the TM5800 can address is 1025MB
1024 MB you mean?
Yes 1024MB, pardon the typo.
If only 1 GB can go in DIMM sockets, where can the remaining 3 GB go?
Nowhere. All the DDR memory controller in the TM5800 can address is 1GB of DDR.
Look at Table #4, page 23, and section 1.2 on page 20, and through 1.2.4 on page 24, TM5800v2.1_databook for an explanation of all this.
Is the memory controller silicon inside the TM5800, or is it some separate chip?
Inside the TM5800. Figure #1, page 10, TM5800v2.1_databook.
Look for modules that that minimize the number of loads.
What are "loads"?
Loads = devices.
Again, the datasheet may list capabilities that may not be available on the mainboard. There may be traces and pads on the board without components soldered in to save costs. The bean counters may drop features off a board after the design has been completed. Leaving out components such as DIMMs or other connectors is an easy way to save on production costs without having to respin the pcb.
The PCB designers may have had problems with traces and parts placement so memory speeds are compromised. Also the datasheet may not list all the problems and workarounds with the device. Issues with cpu's and chipsets are usually in the NDA doc's vs public doc's.
-Bari
If only 1 GB can go in DIMM sockets, where can the remaining 3 GB go?
Nowhere. All the DDR memory controller in the TM5800 can address is 1GB of DDR.
Processor address space != system memory.
Some of that 32-bit address space is reserved for =memory mapped PCI devices, Some of it is allocated to your Graphics card RAM, Some of it accesses the BIOS chip.
In the datasheets there should be a section called something like the processory memory map or system memory map.
This section should outline what ranges of addresses are reserved for what. The board designers may also have special areas that are reserved.
What are "loads"?
Loads = devices.
Thats EE speak for how many devices you can control on a bus. Heres a really gross oversimplification way to think about it. Consider the water coming into your home or apartment. Only so much water can make it into your home via the incomming pipe. Each time you turn on a tap the flow rate of the water reduces. So when the washing machine is on, the dishwasher is on, and somebody flushes the poor soul in the shower gets almost no water pressure.
Each one of those items is a "load." Each system can only support so many loads before one part of the system suffers or just dosen't work at all.
Again, the datasheet may list capabilities that may not be available on the mainboard. There may be traces and pads on the board without
Like Bari says, A high speed memory system is a _really_ tricky thing to get right. In fact I'm somewhat amazed we get them to work at all. At 200 Mhz a clock dosen't look like a clock anymore. And you violate timing specs if things are just a few nano-seconds (10E-9) off. If the manual lists things a certain way then in general thats the way they need to be or your in for trouble.
Memory aside, I thought there were issues with the transmeta parts and not enough documentation from transmeta?
-- Richard A. Smith
Richard Smith smithbone@gmail.com wrote:
Memory aside, I thought there were issues with the transmeta parts and not enough documentation from transmeta?
And aside memory, can I currently flash this board with LinuxBIOS, and how to safely do it, provided the flash part is soldered? I don't wan't to make it useless.
It has to be a standard desktop computer, with video (may be framebuffer), USB keyboard, IDE not essenstial, I can have only network boot and USB flash disk.
0000:00:00.0 Host bridge: Transmeta Corporation LongRun Northbridge (rev 03) 0000:00:00.1 RAM memory: Transmeta Corporation SDRAM controller 0000:00:00.2 RAM memory: Transmeta Corporation BIOS scratchpad 0000:00:0d.0 VGA compatible controller: ATI Technologies Inc Rage XL (rev 27) 0000:00:11.0 ISA bridge: VIA Technologies, Inc. VT8231 [PCI-to-ISA Bridge] (rev 10) 0000:00:11.1 IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE (rev 06) 0000:00:11.2 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 1e) 0000:00:11.3 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 1e) 0000:00:11.4 Bridge: VIA Technologies, Inc. VT8235 ACPI (rev 10) 0000:00:11.5 Multimedia audio controller: VIA Technologies, Inc. VT82C686 AC97 Audio Controller (rev 40) 0000:00:12.0 Ethernet controller: VIA Technologies, Inc. VT6102 [Rhine-II] (rev 51)
Below are the main components on the motherboard:
P558 M/B (motherboard) 02157-1. 48.3B201 .011 MADE IN CHINA
CATAC 84V-0 E217196 CTML-1 041503
U8 (PHY) VIA VT6103 0408CD TAIWAN 2HF0443886
U4 (AUDIO) VIA VT1612A 0406CD TAIWAN 2HA4426311
U15 (Southbridge) VIA VT8231 0409CD TAIWAN 13H017100
U21 (VIDEO) ATI RAGE XL 215R3LASB41 DE5541.00 0340AA TAIWAN
U16 (BIOS 2 MB) ---------------- MX B041172 29LV160ATTC-90 2J031300 TAIWAN
on sticker: P558 U16 V1.09-733 ----------------
U18 (CPU) ---------------- TRANSMETA CRUSOE 5800A073310
301320 101070 0402
A1D23
B610K -2 DD2643.00 TAIWAN ----------------
U20 (2Mx32 = 8MB RAM) 0412 3-2 MT 48LC2M32B2 TG -6 F
Did anyone do it? Do you recommend just to try it, and what rescue options will I have if it goes wrong?
-
Bari Ari -
Miernik -
Richard Smith